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CVE-2026-42273

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

High7.8EPSS 0.30%
Published
Updated
Reserved
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 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.

Scores

CVSS scores of CVE-2026-42273, by who scored it
Scored byCVSSScoreVector
GitHub_MCNA (assigner)4.0High7.8CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:N/SC:H/SI:H/SA:N
NVDNVD · Deferred4.0High7.8CVSS: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
EPSS (exploitation in 30 days)
0.30% · top 77% of all CVEs (6 Nov 2026)
CISA SSVC
Exploitation: none · Automatable: yes · Technical impact: partial
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The list uses the assigner's score when there is one, then CISA's, then NVD's: High 7.8.

Weakness

Affected products

Affected packages

From reviewed advisories of the GitHub Advisory Database.

References (4)

Sources

The same CVE in the primary databases and aggregators, to check against.

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Record last updated .