Is CVE-2026-42273 actively exploited?

No active exploitation of CVE-2026-42273 has been confirmed so far. Continue monitoring, as exploit status can change.

Can CVE-2026-42273 be exploited remotely?

Yes. CVE-2026-42273 is exploitable remotely over the network (CVSS attack vector: Network).

What is the CVSS score of CVE-2026-42273?

CVE-2026-42273 has a CVSS score of 7.8 (HIGH).

HOME VULNERABILITIESCVE-2026-42273

HIGH

CVE-2026-42273

CWE-178Published: May 8, 2026· Updated: May 8, 2026

7.8

CVSS v3.1

EPSS:0.04%probability of exploitation in 30 daysPercentile:12.9th

Official 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.

NVD Source

Technical Analysis

CVE-2026-42273 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.

The vulnerability requires no privileges and no user interaction, making it a prime target for automated exploitation campaigns and worm-like propagation.

CVSS v3.1 Vector Breakdown

Exploitability

Attack VectorNetwork

Attack ComplexityLow

Privileges Req.None

User InteractionNone

ScopeX

Impact

Confidentiality

Integrity

Availability

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