Symfony: Security Firewall Bypass via failure_forward Subrequest: Unauthenticated Access to access_control-Protected GET Routes

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS

not scored

EPSS

• CVE-2026-48489: 0.60% estimated exploitation activity in the next 30 days; percentile 48.56 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

Description When a firewall is configured with form-login (or any authenticator using DefaultAuthenticationFailureHandler) and the failureforward: true option, the handler reads the failurepath parameter from the failing login request and uses it as the path of an internal subrequest dispatched through HttpKernelInterface::SUBREQUEST. 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 accesscontrol) does not run. Because the attacker controls the target of the subrequest, an unauthenticated POST to the check path with failurepath=/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 accesscontrol rules (e.g. ^/admin requires…

Published by the source

15 Jun 2026, 17:28 UTC

Last modified by the source

15 Jun 2026, 17:28 UTC

Source last checked

26 Oct 2026, 14:49 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-6h46-9jf5-q59x

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# Patch Next advisory brief: CVE-2026-48489

Advisory: Symfony: Security Firewall Bypass via failure_forward Subrequest: Unauthenticated Access to access_control-Protected GET Routes
IDs: CVE-2026-48489, GHSA-6h46-9jf5-q59x
Record: https://patchnext.com/advisories/cve-2026-48489 (revision 1, source checked 26 Oct 2026, 14:49 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Unrated
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: symfony/symfony 8.0.13, 7.4.13, 6.4.41, 5.4.53; symfony/security-http 8.0.13, 7.4.13, 6.4.41, 5.4.53. A vendor fix does not mean a deployment is fixed.

## Affected components
- Packagist symfony/symfony: affected < 5.4.53; >= 6.0.0, < 6.4.41; >= 7.0.0, < 7.4.13; >= 8.0.0, < 8.0.13; fixed in 6.4.41, 8.0.13, 7.4.13, 5.4.53
- Packagist symfony/security-http: affected < 5.4.53; >= 6.0.0, < 6.4.41; >= 7.0.0, < 7.4.13; >= 8.0.0, < 8.0.13; fixed in 6.4.41, 8.0.13, 7.4.13, 5.4.53

## Suggested inspection (read-only)
- Packagist symfony/symfony: check the installed version with your package manager.
- Packagist symfony/security-http: check the installed version with your package manager.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on symfony/symfony, symfony/security-http.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-6h46-9jf5-q59x (GitHub-reviewed advisory GHSA-6h46-9jf5-q59x lists affected ranges: Packagist symfony/security-http >=0 =6.0.0 =7.0.0 =8.0.0 =0 =6.0.0 =7.0.0 =8.0.0 <8.0.13)

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