GHSA-m837-xvxr-vqwg
GHSA-m837-xvxr-vqwg is a CWE-346 vulnerability in flowise. O3 Security confirms whether GHSA-m837-xvxr-vqwg is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
Flowise: Hardcoded CORS wildcard on TTS endpoint enables cross-origin credential abuse from any webpage
Exploitation Status
No confirmed exploitation observed yet
- CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
- CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.
Exploitation and automatability from CISA’s SSVC triage for GHSA-m837-xvxr-vqwg.
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
Real-World Exposure
How broadly this vulnerability is actually deployed: weekly install volume shows current usage, and reverse-dependency count shows how many other packages break if it stays unpatched.
flowisenpmDescription
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.tsline 83
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | flowise | all versions | 3.1.2 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for flowise. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update flowise to 3.1.2 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-m837-xvxr-vqwg is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether GHSA-m837-xvxr-vqwg is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to GHSA-m837-xvxr-vqwg. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is GHSA-m837-xvxr-vqwg in your dependencies?
O3 detects GHSA-m837-xvxr-vqwg across npm dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.