CVE-2026-42274
Heimdall is a cloud native Identity Aware Proxy and Access Control Decision service.
Impact
Heimdall is a cloud native Identity Aware Proxy and Access Control Decision service. Prior to version 0.17.14, Heimdall 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. 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). This issue has been patched in version 0.17.14.
Affected packages
| Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|
| go | github.com/dadrus/heimdall | < 0.17.14 | 0.17.14 |
Weakness classification
References
- NVD record
- CVE.org record
- GitHub advisory
- https://github.com/advisories/GHSA-3q34-rx83-r6mq
- https://github.com/dadrus/heimdall/security/advisories/GHSA-3q34-rx83-r6mq
- 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
- 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/releases/tag/v0.17.14