CVE-2026-42274: Dadrus Heimdall

High severity, CVSS 7.8. EPSS: 0.5% chance of exploitation in the next 30 days.

Heimdall is a cloud native Identity Aware Proxy and Access Control Decision service. Prior to version 0.17.14, Heimdall performs rule matching on the raw (non-normalized) request path, while downstream components may normalize dot-segments according to RFC 3986, Section 6.2.2.3. This discrepancy can result in heimdall authorizing a request for one path (e.g., /user/../admin, or URL-encoded variants such as /user/%2e%2e/admin or /user/%2e%2e%2fadmin. The latter would require the allow_encoded_slashes option to be set to on or no_decode.) while the downstream ultimately processes a different, normalized path (/admin). This issue has been patched in version 0.17.14.

Affected products

• Dadrus Heimdall: before 0.17.14 (fixed in 0.17.14)

Published 2026-05-08. Last modified 2026-06-17.