p PatchFirst

CVE-2026-57210

CVE-2026-57210 · Heimdall: IP Spoofing via Unvalidated Forwarding Headers

This page contains facts from public vulnerability sources. Check the original advisory before updating.

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.

CVSS 7.0 · High

Published
Updated

Affected products and versions

  • heimdall

    Versions
    • < 0.17.17: Affected

    No fix published

Original sources

Check your server →