GHSA-6h46-9jf5-q59x
Fix: symfony/symfony@c48a427GHSA-6h46-9jf5-q59x is a CWE-863 vulnerability in symfony/security-http. O3 Security confirms whether GHSA-6h46-9jf5-q59x is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
Symfony: Security Firewall Bypass via failure_forward Subrequest: Unauthenticated Access to access_control-Protected GET Routes
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-6h46-9jf5-q59x.
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
symfony/security-http🐘symfony/symfony🐘symfony/security-http🐘symfony/security-http🐘symfony/security-http🐘symfony/symfony🐘symfony/symfony🐘symfony/symfonyReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects Packagist packages — download data is not available via public APIs for these ecosystems.
Description
Description
When a firewall is configured with form-login (or any authenticator using DefaultAuthenticationFailureHandler) and the failure_forward: true option, the handler reads the _failure_path parameter from the failing login request and uses it as the path of an internal subrequest dispatched through HttpKernelInterface::SUB_REQUEST.
Symfony's Firewall::onKernelRequest listener intentionally skips subrequests under the assumption they are internally generated and trusted, which also means AccessListener (the listener that evaluates access_control) does not run. Because the attacker controls the target of the subrequest, an unauthenticated POST to the check path with _failure_path=/admin/whatever performs a local request forgery that executes the target controller outside the firewall perimeter and returns its response to the caller.
Applications that follow Symfony's recommended best practice of protecting administrative areas with broad access_control rules (e.g. ^/admin requires ROLE_ADMIN) and expose read-only GET endpoints under that area (data exports, internal APIs, account views) are fully exposed: any such GET route can be read by an unauthenticated attacker without any developer misconfiguration, debug mode, or state-changing GET handler being required.
Resolution
DefaultAuthenticationFailureHandler no longer honors the request-supplied _failure_path parameter when failure_forward is enabled. The subrequest is always dispatched to the configured failure_path option (defaulting to login_path), which is set by the application owner and not by the request. The redirect branch (failure_forward: false) is unchanged because redirects re-enter the firewall on the next request and are not subject to this bypass.
The patch for this issue is available here for branch 5.4.
Credits
Symfony would like to thank Nguyen Ngoc Toan Thang (@a-tt-om) and Tran Quoc Tri Trung (@teebow1e) for reporting the issue, and Nicolas Grekas for providing the fix.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐘Packagist | symfony/security-http | all versions | 5.4.53 |
| 🐘Packagist | symfony/symfony | all versions | 5.4.53 |
| 🐘Packagist | symfony/security-http | ≥ 6.0.0&&< 6.4.41 | 6.4.41 |
| 🐘Packagist | symfony/security-http | ≥ 7.0.0&&< 7.4.13 | 7.4.13 |
| 🐘Packagist | symfony/security-http | ≥ 8.0.0&&< 8.0.13 | 8.0.13 |
| 🐘Packagist | symfony/symfony | ≥ 6.0.0&&< 6.4.41 | 6.4.41 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for symfony/security-http. 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 symfony/security-http to 5.4.53 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-6h46-9jf5-q59x 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-6h46-9jf5-q59x 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-6h46-9jf5-q59x. 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-6h46-9jf5-q59x in your dependencies?
O3 detects GHSA-6h46-9jf5-q59x across Packagist dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.