Heimdall is a cloud native Identity Aware Proxy and Access Control Decision service. Prior to version 0.17.17, when the trusted_proxies option is configured, heimdall extracts client IP addresses from the Forwarded (for= parameter) and X-Forwarded-For headers and exposes them as Request.ClientIPAddresses to the rule pipeline. However, extracted values are not validated to be syntactically valid IP addresses. Arbitrary strings, malformed IP literals, and RFC 7239 unknown values and obfuscated identifiers are accepted without further checks. In addition, the Forwarded header parser splits on , and ; without accounting for RFC 7239 quoted strings, which can cause a single quoted value to be parsed as multiple entries, with fragments — including trailing quote characters — treated as independent addresses. This issue has been patched in version 0.17.17.
Metrics
Affected Vendors & Products
References
History
Thu, 29 Oct 2026 03:30:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Metrics |
ssvc
|
Fri, 23 Oct 2026 14:00:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| First Time appeared |
Dadrus
Dadrus heimdall |
|
| Vendors & Products |
Dadrus
Dadrus heimdall |
Fri, 23 Oct 2026 12:45:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Description | Heimdall is a cloud native Identity Aware Proxy and Access Control Decision service. Prior to version 0.17.17, when the trusted_proxies option is configured, heimdall extracts client IP addresses from the Forwarded (for= parameter) and X-Forwarded-For headers and exposes them as Request.ClientIPAddresses to the rule pipeline. However, extracted values are not validated to be syntactically valid IP addresses. Arbitrary strings, malformed IP literals, and RFC 7239 unknown values and obfuscated identifiers are accepted without further checks. In addition, the Forwarded header parser splits on , and ; without accounting for RFC 7239 quoted strings, which can cause a single quoted value to be parsed as multiple entries, with fragments — including trailing quote characters — treated as independent addresses. This issue has been patched in version 0.17.17. | |
| Title | Heimdall: IP Spoofing via Unvalidated Forwarding Headers | |
| Weaknesses | CWE-116 CWE-20 CWE-290 |
|
| References |
| |
| Metrics |
cvssV4_0
|
Status: PUBLISHED
Assigner: GitHub_M
Published: 2026-10-23T12:28:09.427Z
Updated: 2026-10-29T02:57:12.693Z
Reserved: 2026-06-24T02:00:46.801Z
Link: CVE-2026-57210
Updated: 2026-10-29T02:57:08.581Z
Status : Deferred
Published: 2026-10-23T13:17:11.847
Modified: 2026-10-23T19:57:42.660
Link: CVE-2026-57210
No data.