Vulnerability in Golang Go
CVE-2026-27137
When verifying a certificate chain which contains a certificate containing multiple email address constraints which share common local portions but different domain portions, these constraints will not be properly applied, and only the last constraint will be considered.
Vulnerability class: Improper Certificate Validation
EPSS: 0.006 (45.5th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.
Affected products
- Golang Go — versions 1.26.0
- Go Standard Library Crypto/x509 — versions 1.26.0-0
Weakness classification (CWE)
References
- security@golang.org (Mailing List)
- security@golang.org (Issue Tracking)
- security@golang.org (Release Notes)
- security@golang.org (Vendor Advisory)
- 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
- 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
- 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
- 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
- 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
- 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
Frequently asked questions
- What is CVE-2026-27137?
- CVE-2026-27137 is a high-severity vulnerability in Golang Go, classified under Improper Certificate Validation. CVSS score: 7.5/10. Published 2026-03-06.
- How severe is CVE-2026-27137?
- High severity. CVSS v3 base score is 7.5 out of 10.