Answer in brief
CVE-2026-57210 records a High severity (CVSS 7.0) vulnerability in Heimdall: IP Spoofing via Unvalidated Forwarding Headers. The current sources do not mark it as known exploited. The current feed maps dadrus/heimdall (generic), github.com/dadrus/heimdall (go), https://github.com/dadrus/heimdall (go), https://github.com/dadrus/heimdall (go). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
CVSS is 7.0. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps dadrus/heimdall (generic), github.com/dadrus/heimdall (go), https://github.com/dadrus/heimdall (go), https://github.com/dadrus/heimdall (go). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| dadrus/heimdallgeneric | <0.17.17 | 0.17.17 |
| github.com/dadrus/heimdallgo | >=0 <0.17.17 | 0.17.17 |
| https://github.com/dadrus/heimdallgo | <=0.17.16 | 0.17.17 |
| https://github.com/dadrus/heimdallgo | >=0 <0.17.17 | 0.17.17 |
Published upstream
Oct 23, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Oct 23, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Jun 19, 2026
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.
Quoted source text, attributed separately from HOL analysis.