{"id":"GHSA-3q34-rx83-r6mq","revision":"615fdd53c477474ea3f63b0256cbc2e3","records":[{"revision":"615fdd53c477474ea3f63b0256cbc2e3","observedAt":"2026-10-24T13:19:41.952+00:00","statement":{"source":"osv","id":"GHSA-3q34-rx83-r6mq","aliases":["CVE-2026-42274","GO-2026-5097"],"title":"Heimdall has an authorization bypass via path normalization mismatch","description":"### Summary\n\nHeimdall performs rule matching on the raw (non-normalized) request path, while downstream components may normalize dot-segments according to [RFC 3986, Section 6.2.2.3](https://www.rfc-editor.org/rfc/rfc3986#section-6.2.2.3). This discrepancy can result in heimdall authorizing a request for one path (e.g., `/user/../admin`, or URL-encoded variants such as `/user/%2e%2e/admin` or `/user/%2e%2e%2fadmin`. The latter would require the `allow_encoded_slashes` option to be set to `on` or `no_decode`.) while the downstream ultimately processes a different, normalized path (`/admin`).\n\n### Details\n\nThis vulnerability can be exploited by an adversary if rule matching is performed using free (named or unnamed) wildcards without further constraints, as shown in the example snippets below.\n\n```yaml\nid: rule-1\nmatch:\n  routes:\n    - path: /user/**\nexecute: # configured to require authentication and authorization\n  # ...\n```\n\n```yaml\nid: rule-2\nmatch:\n  routes:\n    - path: /public/**\nexecute: # configured to allow anonymous access\n  # ...\n```\n\nIf an adversary sends a request to `/public/../user/whatever`, rule-2 will be matched and executed. The downstream service may, however, normalize the request path and interpret it as `/user/whatever`.\n\n### Impact\n\nBypass of access control policies enforced by heimdall may lead to the following consequences:\n\n* Access to or modification of data that should be restricted\n* Invocation of functionality that is expected to require authentication or authorization\n* In certain configurations, escalation of privileges depending on the exposed functionality\n\n### Workarounds\n\n* Normalize HTTP paths or reject HTTP paths containing relative path expressions in the layers in front of Heimdall - this is good practice anyway. Some proxies do that by default, such as Traefik; others, such as Envoy, require additional configuration (for Envoy see [`normalize_path`](https://www.envoyproxy.io/docs/envoy/latest/api-v3/extensions/filters/network/http_connection_manager/v3/http_connection_manager.proto#envoy-v3-api-field-extensions-filters-network-http-connection-manager-v3-httpconnectionmanager-normalize-path)).\n* Include the ID of the rule expected to be executed in the JWT issued by heimdall and check that value in the consuming project's service.","state":0,"publishedAt":"2026-04-25T23:30:46+00:00","modifiedAt":"2026-06-25T18:56:30.2000516+00:00","affected":[{"ecosystem":"Go","name":"github.com/dadrus/heimdall","ranges":[{"type":"SEMVER","events":[{"kind":"introduced","version":"0"},{"kind":"fixed","version":"0.17.14"}]}],"versions":[],"rawVersionEvidence":null}],"metrics":[{"system":"CVSS_V4","vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:N/SC:H/SI:H/SA:N","score":null,"severity":null},{"system":"Publisher rating","vector":null,"score":null,"severity":"HIGH"}],"references":["https://github.com/dadrus/heimdall/security/advisories/GHSA-3q34-rx83-r6mq","https://nvd.nist.gov/vuln/detail/CVE-2026-42274","https://github.com/dadrus/heimdall/pull/3209","https://github.com/dadrus/heimdall/commit/b5dfa484b7a8c2ce6d8691c026f9da867719947a","https://github.com/dadrus/heimdall","https://github.com/dadrus/heimdall/releases/tag/v0.17.14","https://www.envoyproxy.io/docs/envoy/latest/api-v3/extensions/filters/network/http_connection_manager/v3/http_connection_manager.proto#envoy-v3-api-field-extensions-filters-network-http-connection-manager-v3-httpconnectionmanager-normalize-path","https://www.rfc-editor.org/rfc/rfc3986#section-6.2.2.3"],"sourceUrl":"https://github.com/advisories/GHSA-3q34-rx83-r6mq","license":"GitHub Advisory Database · CC-BY-4.0","key":"osv:GHSA-3q34-rx83-r6mq","identifiers":["GHSA-3q34-rx83-r6mq","CVE-2026-42274","GO-2026-5097"]},"retained":false,"historicalAffected":[]}],"coverage":[]}