CVE-2026-42272

Heimdall: Case-sensitive handling of URL-encoded slashes may lead to inconsistent path interpretation

Published May 8, 2026 CVSS 4.0 · 7.8 High EPSS < 1% KEV · Not listed
Description
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.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

Source ID Title
Github GHSA Github GHSA GHSA-43jv-5j4x-qv67 Heimdall: Case-sensitive handling of URL-encoded slashes may lead to inconsistent path interpretation
History
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'none', 'Technical Impact': 'total'}, 'version': '2.0.3'}

Type Values Removed Values Added
First Time appeared Dadrus
Dadrus heimdall
Vendors & Products Dadrus
Dadrus heimdall
Type Values Removed Values Added
Description 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.
Title Heimdall: Case-sensitive handling of URL-encoded slashes may lead to inconsistent path interpretation
Weaknesses CWE-178
CWE-436
References
Metrics cvssV4_0

{'score': 7.8, 'vector': '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'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
GitHub_M
Published
Updated
May 8, 2026, 11:12 PM
Reserved
Apr 26, 2026, 11:53 AM
Status
Deferred
Published
May 8, 2026, 4:16 AM
Modified
Oct 26, 2026, 8:10 PM