CVE-2026-82477

Heimdall prior to version 0.17.14 performs rule matching on the raw request path, which may lead to unauthorized access. Due to the discrepancy in path normalization, Heimdall may authorize requests for one path while downstream components process a different, normalized path.

Heimdall, an identity-aware proxy and access control service, prior to version 0.17.14, performed host matching in a case-sensitive manner, which is inconsistent with the fact that HTTP hostnames are case-insensitive. This can lead to misclassification of requests that differ only in letter casing.

Heimdall, a proxy and access control service, prior to version 0.17.14 handled URL-encoded slashes in a case-sensitive manner, leading to request path interpretation issues. As a result, the lowercase equivalent (%2f) was not recognized, potentially resulting in authorization bypass.

linuxserver Heimdall through 2.8.3 applies its SafeUrlFetcher SSRF protection only to ItemController; the enhanced-application test and live-stats requests occur via SupportedApps::execute(), a GuzzleHttp client that lacks IP address restrictions. In some realistic installations, the POST /test_config (and GET /get_stats) endpoints are accessible through CSRF, allowing an unauthenticated attacker to force the server to send requests to arbitrary internal hosts and ports (including 169.254.169.254) and read a status/port oracle in addition to partial response data.