CVE-2026-42273

HIGH

Heimdall: Case-sensitive host matching may lead to policy bypass

Title source: cna
STIX 2.1

Description

Heimdall is a cloud native Identity Aware Proxy and Access Control Decision service. Prior to version 0.17.14, Heimdall performs host matching in a case-sensitive manner, while HTTP hostnames are case-insensitive. This discrepancy can result in heimdall failing to match a rule for a request host that differs only in letter casing, potentially causing the request to be classified differently than intended. This issue has been patched in version 0.17.14.

References (4)

Core 4

Scores

CVSS v4 7.8
EPSS 0.0030
EPSS Percentile 21.5%
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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

CISA SSVC

Vulnrichment
Exploitation none
Automatable yes
Technical Impact partial

Details

CWE
CWE-178 CWE-436
Status published
Products (2)
dadrus/heimdall 0 - 0.17.14Go
dadrus/heimdall < 0.17.14
Published May 08, 2026
Tracked Since May 08, 2026