AI and data stack advisories

Severe, 6 weeks1496Projects326

1496 severe, 6 weeks · 326 projects

FlowiseGHSA-m837-xvxr-vqwg

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

Flowise

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

Medium
Fix: upgrade to 3.1.2 or later
GitHub advisory

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

Affected versions

PackageAffectedFixed in
flowise
npm
< 3.1.23.1.2
Details and references
CVSS 4.0
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N
Severity from
GitHub (reviewed advisory)
Weakness
CWE-942
Also known as
CVE-2026-56277

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