CVE-2026-42274highCWE-35CWE-436

CVE-2026-42274: high-severity vulnerability in dadrus heimdall

Heimdall: Authorization bypass via path normalization mismatch

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21Vexday Risk Score

No sign of exploitation. No public exploitation artifact known so far.

ssvc Trackcvss 7.8epss 0.4%
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.
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:N/SC:H/SI:H/SA:N
Affected products
dadrus · heimdall
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