CVE-2026-42273 HIGH

CVE-2026-42273: Heimdall: Case-sensitive host matching may lead to policy bypass

Vendor Dadrus
Product heimdall
Weakness CWE-436
Published May 8, 2026
Last update May 8, 2026
View on NVD All CVEs

CVSS base score

7.8/10
Attack vector Network
Attack complexity Low
Privileges required None
User interaction None
Confidentiality —
Integrity —

CVSS 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

What the vulnerability does

01Description

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.

Key dates

02Disclosure timeline

May 8, 2026 CVE published
May 8, 2026 Record updated