GHSA-M837-XVXR-VQWG

Vulnerability from github – Published: 2026-05-20 15:38 – Updated: 2026-05-20 15:38
VLAI
Summary
Flowise: Hardcoded CORS wildcard on TTS endpoint enables cross-origin credential abuse from any webpage
Details

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

// 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:

// 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
Severity
6.9 (Medium)
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
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{
  "affected": [
    {
      "database_specific": {
        "last_known_affected_version_range": "\u003c= 3.1.1"
      },
      "package": {
        "ecosystem": "npm",
        "name": "flowise"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "3.1.2"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [],
  "database_specific": {
    "cwe_ids": [
      "CWE-942"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-05-20T15:38:02Z",
    "nvd_published_at": null,
    "severity": "MODERATE"
  },
  "details": "### Summary\n\nThe TTS generation endpoint sets `Access-Control-Allow-Origin: *` as a hardcoded response header, independent of the server\u0027s 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(\u0027Access-Control-Allow-Origin\u0027, \u0027*\u0027)\nres.setHeader(\u0027Access-Control-Allow-Headers\u0027, \u0027Cache-Control\u0027)\n```\n\n### Impact\n\n- Cross-origin credential abuse \u2014 any webpage can trigger TTS using stored credentials\n- Bypasses the server\u0027s 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\u0027s CORS middleware handle the headers:\n\n```typescript\n// Remove these lines:\n// res.setHeader(\u0027Access-Control-Allow-Origin\u0027, \u0027*\u0027)\n// res.setHeader(\u0027Access-Control-Allow-Headers\u0027, \u0027Cache-Control\u0027)\n```\n\n---\n\n## References\n\n- `packages/server/src/controllers/text-to-speech/index.ts` line 83",
  "id": "GHSA-m837-xvxr-vqwg",
  "modified": "2026-05-20T15:38:02Z",
  "published": "2026-05-20T15:38:02Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/FlowiseAI/Flowise/security/advisories/GHSA-m837-xvxr-vqwg"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/FlowiseAI/Flowise"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "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",
      "type": "CVSS_V4"
    }
  ],
  "summary": "Flowise: Hardcoded CORS wildcard on TTS endpoint enables cross-origin credential abuse from any webpage"
}



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