GHSA-4r4r-4jp4-wwf9
CRITICALFUXA has JWT Authentication Bypass via HTTP Referer header spoofing
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.
Blast Radius
Weekly download volume for affected packages — a proxy for how broadly this vulnerability is deployed.
@frangoteam/fuxanpmDescription
FUXA 1.2.8 and prior contains an Authentication Bypass vulnerability leading to Remote Code Execution (RCE). The vulnerability exists in the server/api/jwt-helper.js middleware, which improperly trusts the HTTP "Referer" header to validate internal requests. A remote unauthenticated attacker can bypass JWT authentication by spoofing the Referer header to match the server's host. Successful exploitation allows the attacker to access the protected /api/runscript endpoint and execute arbitrary Node.js code on the server.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | @frangoteam/fuxa | all versions | No fix |
Research use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.
FUXA 1.2.8 - Authentication Bypass + RCE Exploit
by joshua · Apr 30, 2026
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for @frangoteam/fuxa. 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.
Remediation status
No patched version of @frangoteam/fuxa has shipped for GHSA-4r4r-4jp4-wwf9 yet. Where your build allows, override or pin the dependency away from the vulnerable range, and apply any maintainer-recommended mitigation.
Mitigate without a patch
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-4r4r-4jp4-wwf9 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-4r4r-4jp4-wwf9. 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-4r4r-4jp4-wwf9 in your dependencies?
O3 detects GHSA-4r4r-4jp4-wwf9 across npm dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.