CVE-2026-118516

LOWCVSS 6.3 · MEDIUM

Signal is active with 1 mentions in latest observed window

Immediate actions

  • Track advisory updates for patch or workaround availability

Recommended action window: Monitor and triage in normal cycle

NVD 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.

0.0/ 10 priority

Sources & remediation

Weakness type (CWE)
CWE-436CWE-863

Priority

LOW

Exploitation

NONE

PoC

NONE

Patch

NONE

Momentum

NONE

Threat summary

  • 1 mentions across 1 observed day

What's happening

  • 1 total mentions across 1 day

Deep dive

Activity timeline1 mentions / 1d
00111Mentions · 2026-11-06: 111-06
Referenced assets1 URL
Full discourse1 post
  • Kamel – CTO as a Service - Expert IT@kamel_laimene

    Symfony Routing : mettez à jour, puis videz le cache. Un placeholder d'hôte peut manger le début du chemin et contourner vos règles /admin (firewall, access_control). Passez en 5.4.56, 6.4.50, 7.4.23 ou 8.1.11, sinon le cache garde l'ancienne version. https://symfony.com/blog/cve-2026-118516-host-placeholders-can-match-the-start-of-the-path-in-compiled-url-matchers-bypassing-path-rules

    0000040
    66 followersView on X

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