High 7.5Published Dec 2, 2025

CVE-2025-61729Excessive resource consumption when printing error string for host certificate validation in crypto/x509

Updated under an hour ago (Oct 27, 2026, 3:10 AM ET)

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It affects Go standard library crypto/x509 and 1 other product. Add what you run to find out whether that includes you.

No exploitation reported and no EPSS estimate yet.

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Every CVE for Go standard library crypto/x509

Exploited in the last 30 days

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.

CVSS: 7.5 HIGH (v3.1, CISA ADP)CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Weakness (CWE): CWE-400
Known exploited: Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days): Not loaded for this CVE
Assigned by: Go
NVD analysis: Analyzed
Record last updated: Dec 3, 2025
First seen by InfoSec Signals: Oct 9, 2026

Affected products

Affected products

Go standard library crypto/x509 go_standard_library:crypto_x509 (from the name)	before 1.24.11; from 1.25.0 before 1.25.5	CNA record
golang go golang:go	before 1.24.11; from 1.25.0 before 1.25.5	NVD

References

References

https://go.dev/cl/725920	patch
https://go.dev/issue/76445	issue-tracking, patch
https://groups.google.com/g/golang-announce/c/8FJoBkPddm4	mailing-list, release-notes
https://pkg.go.dev/vuln/GO-2025-4155	vendor-advisory

The CVE record on cve.org NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.