CVE-2025-32431: Github.com/traefik/traefik Traefik Has A Possible Vulnerability Vulnerability

{
  "schema_version" : "1.4.0",
  "id" : "GHSA-6p68-w45g-48j7",
  "modified" : "2025-11-27T08:03:31Z",
  "published" : "2025-04-21T16:17:38Z",
  "aliases" : [ "CVE-2025-32431" ],
  "summary" : "Traefik has a possible vulnerability with its path matchers",
  "details" : "## Impact\n\nThere is a potential vulnerability in Traefik managing the requests using a `PathPrefix`, `Path` or `PathRegex` matcher.\n\nWhen Traefik is configured to route the requests to a backend using a matcher based on the path, if the URL contains a `/../` in its path, it’s possible to target a backend, exposed using another router, by-passing the middlewares chain.\n\n## Example\n\n```yaml\napiVersion: traefik.io/v1alpha1\nkind: IngressRoute\nmetadata:\n  name: my-service\nspec:\n  routes:\n    - match: PathPrefix(‘/service’)\n      kind: Rule\n      services:\n        - name: service-a\n          port: 8080\n      middlewares:\n        - name: my-middleware-a\n    - match: PathPrefix(‘/service/sub-path’)\n      kind: Rule\n      services:\n        - name: service-a\n          port: 8080\n```\n\nIn such a case, the request `http://mydomain.example.com/service/sub-path/../other-path` will reach the backend `my-service-a` without operating the middleware `my-middleware-a` unless the computed path is `http://mydomain.example.com/service/other-path` and should be computes by the first router (operating `my-middleware-a`).\n\n## Patches\n\n- https://github.com/traefik/traefik/releases/tag/v2.11.24\n- https://github.com/traefik/traefik/releases/tag/v3.3.6\n- https://github.com/traefik/traefik/releases/tag/v3.4.0-rc2\n\n## Workaround\n\nAdd a `PathRegexp` rule to the matcher to prevent matching a route with a `/../` in the path.\n\nExample: \n\n```yaml\nmatch: PathPrefix(`/service`) && !PathRegexp(`(?:(/\\.\\./)+.*)`)\n```\n\n## For more information\n\nIf you have any questions or comments about this advisory, please [open an issue](https://github.com/traefik/traefik/issues).",
  "severity" : [ {
    "type" : "CVSS_V4",
    "score" : "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N/E:P"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "Go",
      "name" : "github.com/traefik/traefik"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "last_affected" : "1.7.34"
      } ]
    } ]
  }, {
    "package" : {
      "ecosystem" : "Go",
      "name" : "github.com/traefik/traefik/v2"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "2.11.23"
      } ]
    } ]
  }, {
    "package" : {
      "ecosystem" : "Go",
      "name" : "github.com/traefik/traefik/v3"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "3.3.6"
      } ]
    } ]
  }, {
    "package" : {
      "ecosystem" : "Go",
      "name" : "github.com/traefik/traefik/v3"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "3.4.0-rc1"
      }, {
        "fixed" : "3.4.0-rc2"
      } ]
    } ],
    "versions" : [ "3.4.0-rc1" ]
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/traefik/traefik/security/advisories/GHSA-6p68-w45g-48j7"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2025-32431"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/traefik/traefik/pull/11684"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/traefik/traefik"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/traefik/traefik/releases/tag/v2.11.24"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/traefik/traefik/releases/tag/v3.3.6"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/traefik/traefik/releases/tag/v3.4.0-rc2"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-22" ],
    "severity" : "HIGH",
    "github_reviewed" : true,
    "github_reviewed_at" : "2025-04-21T16:17:38Z",
    "nvd_published_at" : "2025-04-21T16:15:54Z"
  }
}