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The wildcard Access-Control-Allow-Origin header allows any website to make requests to the local server and read chat log data via the search and stats APIs. This restricts CORS to only localhost and 127.0.0.1 origins, preventing cross-origin data access from external sites while preserving normal local usage. Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
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Summary
Access-Control-Allow-Origin: *with an allowlist that only reflectslocalhostand127.0.0.1originsVary: Originheader for correct caching behaviorisLocalhostOrigin()helper with comprehensive test coverageProblem
The wildcard CORS header allows any website visited in the browser to make JavaScript requests to the local API (
/api/search,/api/stats) and read Claude Code chat log data. While the server correctly binds to127.0.0.1, the permissive CORS policy means a malicious site could exfiltrate session data if the server is running.Fix
CORS is now restricted to localhost origins only:
http://localhost/http://localhost:<port>http://127.0.0.1/http://127.0.0.1:<port>Requests from any other origin will not receive CORS headers, so browsers will block cross-origin reads.
Test plan
go test ./...)TestCorsMiddlewareto verify localhost origins are allowed and external origins are rejectedTestIsLocalhostOrigintable-driven test covering localhost, 127.0.0.1, external domains, and edge cases🤖 Generated with Claude Code