GHSA-6H46-9JF5-Q59X
Vulnerability from github – Published: 2026-06-15 17:28 – Updated: 2026-06-15 17:28Description
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.
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],
"aliases": [
"CVE-2026-48489"
],
"database_specific": {
"cwe_ids": [
"CWE-863"
],
"github_reviewed": true,
"github_reviewed_at": "2026-06-15T17:28:20Z",
"nvd_published_at": null,
"severity": "HIGH"
},
"details": "### Description\n\nWhen 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`.\n\nSymfony\u0027s `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.\n\nApplications that follow Symfony\u0027s 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.\n\n### Resolution\n\n`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.\n\nThe patch for this issue is available [here](https://github.com/symfony/symfony/commit/c48a4276309e11aedeeb0ce3a89dfbf0b4fe04ff) for branch 5.4.\n\n### Credits\n\nSymfony 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.",
"id": "GHSA-6h46-9jf5-q59x",
"modified": "2026-06-15T17:28:20Z",
"published": "2026-06-15T17:28:20Z",
"references": [
{
"type": "WEB",
"url": "https://github.com/symfony/symfony/security/advisories/GHSA-6h46-9jf5-q59x"
},
{
"type": "WEB",
"url": "https://github.com/symfony/symfony/commit/c48a4276309e11aedeeb0ce3a89dfbf0b4fe04ff"
},
{
"type": "WEB",
"url": "https://github.com/FriendsOfPHP/security-advisories/blob/master/symfony/security-http/CVE-2026-48489.yaml"
},
{
"type": "WEB",
"url": "https://github.com/FriendsOfPHP/security-advisories/blob/master/symfony/symfony/CVE-2026-48489.yaml"
},
{
"type": "PACKAGE",
"url": "https://github.com/symfony/symfony"
},
{
"type": "WEB",
"url": "https://symfony.com/cve-2026-48489"
}
],
"schema_version": "1.4.0",
"severity": [],
"summary": "Symfony: Security Firewall Bypass via failure_forward Subrequest: Unauthenticated Access to access_control-Protected GET Routes"
}
Sightings
| Author | Source | Type | Date | Other |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or observed by the user.
- Confirmed: The vulnerability has been validated from an analyst's perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
- Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
- Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
- Not confirmed: The user expressed doubt about the validity of the vulnerability.
- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.