CVE-2026-118516
Received
Received - Intake
Authorization Bypass in Symfony Routing Component
Vulnerability report for CVE-2026-118516, including description, CVSS score, EPSS score, affected products, exploitability, helpful resources, and attack-flow context.
Publication date: 2026-11-04
Last updated on: 2026-11-04
Assigner: Checkmarx
Description
Description
The Symfony Routing components CompiledUrlMatcher and UrlMatcher interpret the host and path information differently, allowing path-based authorization rules to be bypassed in Symfony versions prior to 5.4.56, 6.x prior to 6.4.50, 7.x prior to 7.4.23, and 8.x prior to 8.1.11.
For routes that define a host, CompiledUrlMatcher matches the string $host.'.'.$pathinfo against the host regular expression followed by the path regular expression, while UrlMatcher matches the host and the path separately. A host placeholder can therefore match /, and consume the beginning of the path, so the request is routed to a controller, while UrlMatcher would find no route. Rules that look at the path, such as access_control entries and firewall patterns, are evaluated against the actual request path, so they do not apply while the controller of the route runs, potentially allowing an unauthenticated request to reach a protected controller. For example, with the route /admin/report/{id}, the host app.{domain} and the rule access_control: [{ path: ^/admin, roles: ROLE_ADMIN }], an anonymous request for /admin/report/1 is sent to the login page. A request with the Host header app and path /x./admin/report/1 instead reaches the controller, with domain="/x". With the required domain: .+, the real hostname works: app.example.com and /x./admin/report/1 match with domain="example.com./x".
Applications are affected if they have routes with host placeholders protected by path-based rules. With the default requirement, the Host header must be the host of the route without its last labels, such as app: framework.trusted_hosts blocks that, while a web server that only serves known names may not, for instance, Nginx passing the raw Host header to FastCGI for a request line that carries an absolute URI. If the requirement accepts /, such as .+, a real hostname works, and trusted_hosts does not help.
CVSS Scores
EPSS Scores
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Meta Information
Affected Vendors & Products
| Vendor | Product | Version / Range |
|---|---|---|
| sensiolabs | symfony | 0 |
| sensiolabs | symfony | 6 |
| sensiolabs | symfony | 7 |
| sensiolabs | symfony | 8 |
Helpful Resources
Exploitability
CWE
KEV
| CWE ID | Description |
|---|---|
| CWE-863 | The product performs an authorization check when an actor attempts to access a resource or perform an action, but it does not correctly perform the check. |
| CWE-436 | Product A handles inputs or steps differently than Product B, which causes A to perform incorrect actions based on its perception of B's state. |
