fix(mcp): skip empty secret values in redactText#39923
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derodero24 wants to merge 1 commit intomicrosoft:mainfrom
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fix(mcp): skip empty secret values in redactText#39923derodero24 wants to merge 1 commit intomicrosoft:mainfrom
derodero24 wants to merge 1 commit intomicrosoft:mainfrom
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When a secrets .env file contains empty-string values (e.g. from
dotenv parsing comments like `KEY=#{VAR}#`), `replaceAll("", ...)`
inserts the replacement between every character, causing exponential
string growth and a V8 RangeError.
Guard against empty values in both `_redactSecrets` and
`dotenvFileLoader` to prevent the crash.
Fixes microsoft/playwright-mcp#1474
Author
|
@microsoft-github-policy-service agree |
Skn0tt
reviewed
Mar 30, 2026
| for (const [secretName, secretValue] of Object.entries(this._context.config.secrets ?? {})) | ||
| text = text.replaceAll(secretValue, `<secret>${secretName}</secret>`); | ||
| for (const [secretName, secretValue] of Object.entries(this._context.config.secrets ?? {})) { | ||
| if (secretValue) |
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I had to double-check JS truthiness rules to see if this works for "false" or "0", e.g. CI=false. Not the usual secret value, but usual contents of .env. The behaviour is correct, but I expect other readers to stumble over this too. Let's make it easier to reason about:
Suggested change
| if (secretValue) | |
| if (secretValue !== "") |
Suggested change
| if (secretValue) | |
| if (secretValue.length) |
| return undefined; | ||
| return dotenv.parse(fs.readFileSync(value, 'utf8')); | ||
| const parsed = dotenv.parse(fs.readFileSync(value, 'utf8')); | ||
| return Object.fromEntries(Object.entries(parsed).filter(([, v]) => v)); |
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Wouldn't a fix in one of the two locations be enough? Why do we need both?
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That issue was closed |
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Summary
Fixes microsoft/playwright-mcp#1474
Empty-string secret values parsed from
.envfiles (e.g.KEY=#{VAR}#where dotenv strips comments) causeString.replaceAll("", ...)to insert the replacement tag between every character. This grows the string exponentially across multiple empty secrets, crashing V8 with aRangeError.secretValuein_redactSecrets()before callingreplaceAlldotenvFileLoader()at parse timeFixes microsoft/playwright-mcp#1474