Vulnerability in Golang Go
CVE-2025-61729
Within HostnameError.Error(), when constructing an error string, there is no limit to the number of hosts that will be printed out. Furthermore, the error string is constructed by repeated string concatenation, leading to quadratic runtime. Therefore, a certificate provided by a malicious actor can result in excessive resource consumption.
Vulnerability class: Improper Certificate Validation
EPSS: 0.004 (36.2th 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
- Go Standard Library Crypto/x509 — versions 0, 1.25.0
Weakness classification (CWE)
References
- security@golang.org (Patch)
- security@golang.org (Patch, Issue Tracking)
- security@golang.org (Mailing List, Release Notes)
- security@golang.org (Vendor Advisory)
Frequently asked questions
- What is CVE-2025-61729?
- CVE-2025-61729 is a high-severity vulnerability in Golang Go, classified under Improper Certificate Validation. CVSS score: 7.5/10. Published 2025-12-02.
- How severe is CVE-2025-61729?
- High severity. CVSS v3 base score is 7.5 out of 10.