{"id":"CVE-2026-56277","aliases":["GHSA-m837-xvxr-vqwg"],"url":"https://o3.security/vulnerability/CVE-2026-56277","summary":"Flowise - Hardcoded CORS Wildcard in TTS Endpoint","details":"### Summary\n\nThe 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.\n\n### Root Cause\n\n```typescript\n// packages/server/src/controllers/text-to-speech/index.ts:83\nres.setHeader('Access-Control-Allow-Origin', '*')\nres.setHeader('Access-Control-Allow-Headers', 'Cache-Control')\n```\n\n### Impact\n\n- Cross-origin credential abuse — any webpage can trigger TTS using stored credentials\n- Bypasses the server's CORS policy (`getCorsOptions()`) which is otherwise restrictive by default\n- Combined with Finding 3 (TTS credential abuse), enables drive-by credential abuse via malicious webpages\n\n### Suggested Fix\n\nRemove the hardcoded CORS wildcard and let the server's CORS middleware handle the headers:\n\n```typescript\n// Remove these lines:\n// res.setHeader('Access-Control-Allow-Origin', '*')\n// res.setHeader('Access-Control-Allow-Headers', 'Cache-Control')\n```\n\n---\n\n## References\n\n- `packages/server/src/controllers/text-to-speech/index.ts` line 83","published":"2026-06-30T22:08:27.269Z","modified":"2026-08-12T03:51:25.343750173Z","cvss":null,"epss":{"score":0.00136,"percentile":0.03545,"asOf":"2026-08-18"},"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"npm","name":"flowise","fixedVersion":"3.1.2"}],"fix":null,"references":[{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/56xxx/CVE-2026-56277.json"},{"type":"ADVISORY","url":"https://github.com/FlowiseAI/Flowise/security/advisories/GHSA-m837-xvxr-vqwg"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-56277"},{"type":"ADVISORY","url":"https://www.vulncheck.com/advisories/flowise-hardcoded-cors-wildcard-in-tts-endpoint"},{"type":"PACKAGE","url":"https://github.com/FlowiseAI/Flowise"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-08-12T03:51:25.343750173Z"}}