GHSA-fjq3-5pxw-4wj4 is a high-severity (CVSS 8.8) vulnerability in webargs. O3 Security confirms whether GHSA-fjq3-5pxw-4wj4 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
Cross-Site Request Forgery in Webargs
Real-World Exposure
webargs🐍webargsReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects PyPI packages — download data is not available via public APIs for these ecosystems.
Description
flaskparser.py in Webargs 5.x through 5.5.2 doesn't check that the Content-Type header is application/json when receiving JSON input. If the request body is valid JSON, it will accept it even if the content type is application/x-www-form-urlencoded. This allows for JSON POST requests to be made across domains, leading to CSRF.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐍PyPI | webargs | ≥ 5.0.0&&< 5.5.3 | 5.5.3 |
| 🐍PyPI | webargs | ≥ 6.0.0b1&&< 6.0.0b4 | 6.0.0b4 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for webargs. 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 webargs to 5.5.3 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-fjq3-5pxw-4wj4 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-fjq3-5pxw-4wj4 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-fjq3-5pxw-4wj4. 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-fjq3-5pxw-4wj4 in your dependencies?
O3 detects GHSA-fjq3-5pxw-4wj4 across PyPI dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.