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UK Cyber Defence
VulnerabilityAnalyzed

CVE-2026-27138

This can crash programs that are either directly verifying X.509 certificate chains, or those that use TLS.

MEDIUM 5.9EPSS 0.35%

Does this matter?

Lower severity and a low EPSS score (0.35%). Track it; it rarely justifies an emergency change on its own.

Description

Certificate verification can panic when a certificate in the chain has an empty DNS name and another certificate in the chain has excluded name constraints. This can crash programs that are either directly verifying X.509 certificate chains, or those that use TLS.

CVSS 3.1
5.9 MEDIUMCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
EPSS
0.35% probability · 28th percentile
CISA KEV
Not listed
Weakness
CWE-295
Affected
golang/go
Source
security@golang.org

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.