{
  "affected": [
    {
      "database_specific": {
        "last_known_affected_version_range": "\u003c= 5.0.3"
      },
      "package": {
        "ecosystem": "RubyGems",
        "name": "devise"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "5.0.4"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-40295"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-601"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-05-08T15:41:47Z",
    "nvd_published_at": null,
    "severity": "MODERATE"
  },
  "details": "## Summary\n\nWhen the `Timeoutable` module is enabled in Devise, the `FailureApp#redirect_url` method returns `request.referrer` \u2014 the HTTP `Referer` header, which is attacker-controllable \u2014 without validation for any non-GET request that results in a session timeout. An attacker who hosts a page with an auto-submitting cross-origin form can cause a victim with an expired Devise session to be redirected to an arbitrary external URL. This contrasts with the GET timeout path (which uses server-side `attempted_path`) and Devise\u0027s own `store_location_for` mechanism (which strips external hosts via `extract_path_from_location`), both of which are protected; only the non-GET timeout redirect path is unprotected.\n\n## Details\n\nThe vulnerable code is in `lib/devise/failure_app.rb`:\n\n```ruby\ndef redirect_url\n  if warden_message == :timeout\n    flash[:timedout] = true if is_flashing_format?\n\n    path = if request.get?\n      attempted_path          # safe: server-side value from warden options\n    else\n      request.referrer        # UNSAFE: HTTP Referer header, attacker-controlled\n    end\n\n    path || scope_url\n  else\n    scope_url\n  end\nend\n```\n\nThis is passed directly to `redirect_to`:\n\n```ruby\ndef redirect\n  store_location!\n  # ...\n  redirect_to redirect_url   # redirect_url may be an external attacker URL\nend\n```\n\nThe GET timeout path uses `attempted_path`, which is set server-side by Warden and cannot be influenced by the client. The `store_location!` method also only runs for GET requests, so no session-based protection is applied on POST timeouts.\n\nBy contrast, Devise\u0027s `store_location_for` method (used elsewhere) correctly sanitizes URLs via `extract_path_from_location`, which strips the scheme and host.\n\n## Impact\n\n- Victims with expired sessions who click any attacker-crafted link or visit an attacker page with an auto-submitting form are redirected to an arbitrary external URL.\n- The redirect happens transparently via a trusted domain (the target app\u0027s domain), bypassing browser phishing warnings.\n- An attacker can redirect victims to a fake login page to harvest credentials (phishing), or to malicious download sites.\n\n_Note_: Rails\u0027 built-in open-redirect protection does not mitigate this issue. `Devise::FailureApp` is an `ActionController::Metal` app with its own isolated copy of the relevant redirect configuration, so `config.action_controller.action_on_open_redirect = :raise` (and the older `raise_on_open_redirects` setting) do not reach it.\n\n## Patches\n\nThis is patched in Devise v5.0.4. Users should upgrade as soon as possible.\n\n## Workaround\n\nNone beyond upgrading. If an upgrade is not immediately possible, the same changes from the patch commit can be applied as a monkey-patch in a Rails initializer (`Devise::FailureApp#redirect_url` and `Devise::Controllers::StoreLocation#extract_path_from_location`). Remove the monkey-patch after upgrading.",
  "id": "GHSA-jp94-3292-c3xv",
  "modified": "2026-05-08T15:41:47Z",
  "published": "2026-05-08T15:41:47Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/heartcombo/devise/security/advisories/GHSA-jp94-3292-c3xv"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/heartcombo/devise"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N",
      "type": "CVSS_V3"
    }
  ],
  "summary": "Devise has an Open Redirect via Unvalidated `request.referrer` in Timeoutable Session Timeout Handler"
}