VPN blocks Hibernate from connecting to a local PostgreSQL database on macOS

[MAYOT52]

Search first

• I searched and no similar issues were found

Platform/OS

macOS

OS version

Sequoia 15.3.1

Hiddify Version

2.0.5

What Happened?

When using Hiddify VPN on macOS, Hibernate fails to connect to a PostgreSQL database running on localhost. This happens regardless of whether PostgreSQL is:
• Running natively on macOS
• Running inside a Docker container
• Running inside a local VM
Spring application will only work with remote database on another machine

Minimal Reproducible Example (MRE)

1.	Start Hiddify VPN on macOS.
2.	Run a local PostgreSQL database (e.g., with Docker: docker run -p 5432:5432 postgres).
3.	Configure a Spring Boot application with Hibernate and the following datasource URL: `spring.datasource.url=jdbc:postgresql://127.0.0.1:5432/demo`
4.	Start the Spring Boot application.
5.	Observe the connection failure with java.net.UnknownHostException: localhost.
6.	Disconnect VPN (sometimes turn off the application), and notice that the issue is resolved.

Expected Behavior

Hibernate should be able to connect to a local PostgreSQL database (localhost or 127.0.0.1) even when Hiddify VPN is active. The VPN should not interfere with local network connections between applications running on the same machine.

Additional Context

No response

Application Config Options

{
"region": "ru",
"block-ads": false,
"execute-config-as-is": false,
"log-level": "warn",
"resolve-destination": false,
"ipv6-mode": "ipv4_only",
"remote-dns-address": "udp://1.1.1.1",
"remote-dns-domain-strategy": "",
"direct-dns-address": "1.1.1.1",
"direct-dns-domain-strategy": "",
"mixed-port": 12334,
"tproxy-port": 12335,
"local-dns-port": 16450,
"tun-implementation": "mixed",
"mtu": 9000,
"strict-route": true,
"connection-test-url": "http://connectivitycheck.gstatic.com/generate_204",
"url-test-interval": 600,
"enable-clash-api": true,
"clash-api-port": 16756,
"enable-tun": false,
"enable-tun-service": false,
"set-system-proxy": true,
"bypass-lan": false,
"allow-connection-from-lan": false,
"enable-fake-dns": false,
"enable-dns-routing": true,
"independent-dns-cache": true,
"rules": [],
"mux": {
"enable": false,
"padding": false,
"max-streams": 8,
"protocol": "h2mux"
},
"tls-tricks": {
"enable-fragment": false,
"fragment-size": "10-30",
"fragment-sleep": "2-8",
"mixed-sni-case": false,
"enable-padding": false,
"padding-size": "1-1500"
},
"warp": {
"enable": false,
"mode": "proxy_over_warp",
"clean-ip": "auto",
"clean-port": 0,
"noise": "1-3",
"noise-size": "10-30",
"noise-delay": "10-30",
"noise-mode": "m6"
},
"warp2": {
"enable": false,
"mode": "proxy_over_warp",
"clean-ip": "auto",
"clean-port": 0,
"noise": "1-3",
"noise-size": "10-30",
"noise-delay": "10-30",
"noise-mode": "m6"
}
}

Relevant log output

No response

Are you willing to submit a PR? If you know how to fix the bug.

• I'm willing to submit a PR (Thank you!)

[MAYOT52]

It seems that Hiddify might be redirecting localhost traffic through the VPN, causing Hibernate to fail when connecting to a local PostgreSQL database