Skip to content
OpenAdvisories
High · 7.8 CVE-2026-42272 EUVD-2026-28508GHSA-43jv-5j4x-qv67GO-2026-5108

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

Published May 8, 2026 · Updated May 8, 2026 · Assigned by GitHub_M

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.

Affected products

VendorProductAffectedFixed
dadrus heimdall < 0.17.14 —

Fixed in Linux distributions

Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.

ReleasePackageFixed inAdvisory
openSUSE Leap 16.0 govulncheck-vulndb 0.0.20260723T184607-160000.1.1 openSUSE-SU-2026:21483-1

Affected packages

EcosystemPackageAffectedFixedRecord
Go github.com/dadrus/heimdall < 0.17.14 0.17.14 GHSA-43jv-5j4x-qv67

Advisories 1

References