Flowise: Hardcoded CORS wildcard on TTS endpoint enables cross-origin credential abuse from any webpage

MediumCVE-2026-56277 · Published May 20, 2026 · updated Jul 8, 2026

### Summary The TTS generation endpoint sets `Access-Control-Allow-Origin: *` as a hardcoded response header, independent of the server's CORS configuration. This enables any webpage to make cross-origin requests to generate speech using stored credentials. ### Root Cause ```typescript // packages/server/src/controllers/text-to-speech/index.ts:83 res.setHeader('Access-Control-Allow-Origin', '*') res.setHeader('Access-Control-Allow-Headers', 'Cache-Control') ``` ### Impact - Cross-origin credential abuse , any webpage can trigger TTS using stored credentials - Bypasses the server's CORS policy (`getCorsOptions()`) which is otherwise restrictive by default - Combined with Finding 3 (TTS credential abuse), enables drive-by credential abuse via malicious webpages ### Suggested Fix Remove the hardcoded CORS wildcard and let the server's CORS middleware handle the headers: ```typescript // Remove these lines: // res.setHeader('Access-Control-Allow-Origin', '*') // res.setHeader('Access-Control-Allow-Headers', 'Cache-Control') ``` --- ## References - `packages/server/src/controllers/text-to-speech/index.ts` line 83