fix: harden OAuth security (CSRF, XSS, stdio log leak)#384
Merged
zereight merged 1 commit intozereight:mainfrom Mar 22, 2026
Merged
fix: harden OAuth security (CSRF, XSS, stdio log leak)#384zereight merged 1 commit intozereight:mainfrom
zereight merged 1 commit intozereight:mainfrom
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1. Replace Math.random() with crypto.randomUUID() for OAuth state parameters and request IDs — CSRF tokens must be cryptographically unpredictable. 2. HTML-encode the error query parameter in the OAuth callback page to prevent reflected XSS. 3. Redirect pino logger to stderr in oauth.ts to prevent JSON log lines from polluting the MCP stdio transport channel. Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
zereight
approved these changes
Mar 22, 2026
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Summary
Addresses three security findings from a third-party review of the OAuth module:
Math.random()withcrypto.randomUUID()for OAuthstateparameters and request IDs (lines 297, 331, 361) —Math.random()is not a CSPRNG; OAuth state is a CSRF protection token that must be cryptographically unpredictableerrorquery parameter was interpolated directly into HTML (<p>Error: ${error}</p>), enabling reflected XSS on the localhost callback pageindex.tsalready usesdestination: 2; this alignsoauth.tsto matchOne file changed, no new dependencies.
Test plan
npm run test:oauth— 18/18 passing🤖 Generated with Claude Code