Improper certificate validation in Go programming language - CVE-2025-61727
Published: December 6, 2025 / Updated: February 17, 2026
Vulnerability identifier: #VU119236
CSH Severity: Low
CVSS v4.0: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:A/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N/E:U/U:Clear
CVE-ID: CVE-2025-61727
CWE-ID: CWE-295
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vendor: Google
Affected software:
Go programming language
Go programming language
Detailed vulnerability description
The vulnerability allows a remote attacker to perform MitM attack.
The vulnerability exists in crypto/x509 due to incorrect handling of wildcard SANs in the leaf certificate when processing excluded constraint in a certificate chain. A remote attacker can create a specially crafted certificate and bypass implemented domain restrictions and perform MitM or phishing attacks.
How to mitigate CVE-2025-61727
Install updates from vendor's website.