CVE-2026-42272 — Heimdall: Case-sensitive handling of URL-encoded slashes may lead to inconsistent path interpretation
Heimdall is a cloud native Identity Aware Proxy and Access Control Decision service. Prior to version 0.17.14, Heimdall handles URL-encoded slashes (%2F) in a case-sensitive man…
Published: 2026-05-08 · CVSS: 7.8 · CVSS 4.0
Heimdall is a cloud native Identity Aware Proxy and Access Control Decision service. Prior to version 0.17.14, Heimdall handles URL-encoded slashes (%2F) in a case-sensitive manner, while percent-encoding is defined to be case-insensitive. As a result, the lowercase equivalent (%2f) is not recognized and therefore not processed as expected when allow_encoded_slashes is set to off (the default setting). This discrepancy can lead to differences in how request paths are interpreted by heimdall and upstream components, which may result in authorization bypass. This issue has been patched in version 0.17.14.
Source: CVE Program · Revision 8b16575c39f1e1810c5e863010da073d2d3285e7