CVE-2025-61729

Excessive resource consumption when printing error string for host certificate validation in crypto/x509

HIGH
7.5
CVSS Score
Published: December 2, 2025 at 06:54 PM UTC
Updated: October 18, 2026 at 06:10 PM UTC
2 products affected across 2 vendorsGoCrypto/x509

Using crypto/x509 by Go standard library?

Get instant alerts when new vulnerabilities affect crypto/x509 - before attackers find them.

Real-time alertsTrack your software stackFree plan available
Severity
HIGH7.5
Exploit prediction
EPSS 0.5%
SSVC
No known exploit

Description

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.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

v < 1.24.111.25.0 ≤ v < 1.25.5
0 ≤ v < 1.24.111.25.0 ≤ v < 1.25.51.25.0
Affected range stops below 1.24.11, so it looks safe — our inference, not a vendor statement
Affected range stops below 1.25.5, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

References (4)

Patch
Source: cverecord
https://go.dev/cl/725920
Issue TrackingPatch
Source: cverecord
https://go.dev/issue/76445
Mailing ListRelease Notes
Source: cverecord
https://groups.google.com/g/golang-announce/c/8FJoBkPddm4
Vendor Advisory
Source: cverecord
https://pkg.go.dev/vuln/GO-2025-4155

SSVC — Action Prioritization

SSVCNo known exploitNot automatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

7.5HIGHCISA-ADP
Attack Vector
NETWORK
Complexity
LOW
Privileges
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
NONE
Availability
HIGH
Vector?

Quick Info

StatusANALYZED
CWE
CWE-295

Get alerted

Stop reading CVE feeds looking for your own stack

Track the products you run and VulnTracker tells you when a new CVE affects them — with what is known about fixing it, and nothing about the rest.

Free plan, no card