GHSA-99pm-ch96-ccp2 is a medium-severity (CVSS 4.3) Open Redirect vulnerability in flask-appbuilder. O3 Security confirms whether GHSA-99pm-ch96-ccp2 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
Flask-AppBuilder open redirect vulnerability using HTTP host injection
Real-World Exposure
flask-appbuilderReal-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
Impact
Flask-AppBuilder prior to 4.6.2 would allow for a malicious unauthenticated actor to perform an open redirect by manipulating the Host header in HTTP requests.
Patches
Flask-AppBuilder 4.6.2 introduced the FAB_SAFE_REDIRECT_HOSTS configuration variable, which allows administrators to explicitly define which domains are considered safe for redirection.
Examples:
FAB_SAFE_REDIRECT_HOSTS = ["yourdomain.com", "sub.yourdomain.com", "*.yourcompany.com"]
Workarounds
Use a Reverse Proxy to Enforce Trusted Host Headers
References
Are there any links users can visit to find out more?
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐍PyPI | flask-appbuilder | all versions | 4.6.2 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for flask-appbuilder. 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 flask-appbuilder to 4.6.2 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-99pm-ch96-ccp2 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-99pm-ch96-ccp2 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-99pm-ch96-ccp2. 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-99pm-ch96-ccp2 in your dependencies?
O3 detects GHSA-99pm-ch96-ccp2 across PyPI dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.