Denial of Service Vulnerability in Go's Certificate Chain Validation
CVE-2026-32281

7.5HIGH

Key Information:

Vendor

Go Standard Library

Status
Crypto/x509
Vendor
CVE Published:
8 April 2026

What is CVE-2026-32281?

A vulnerability exists in Go's certificate chain validation process that can lead to denial of service. This issue arises when validating certificate chains that contain an excessive number of policy mappings, resulting in inefficient processing. The vulnerability affects trusted certificate chains that are either part of the VerifyOptions.Roots CertPool or included in the system certificate pool. If an attacker exploits this inefficiency, it could cause system instability and service interruptions.

Affected Version(s)

crypto/x509 0 < 1.25.9

crypto/x509 1.26.0-0 < 1.26.2

References

https://go.dev/cl/758061
https://go.dev/issue/78281
https://groups.google.com/g/golang-announce/c/0uYbvbPZRWU

CVSS V3.1

Score:
7.5
Severity:
HIGH
Confidentiality:
None
Integrity:
None
Availability:
None
Attack Vector:
Network
Attack Complexity:
Low
Privileges Required:
None
User Interaction:
None
Scope:
Unchanged

Timeline

  • Vulnerability published

  • Vulnerability Reserved

Credit

Jakub Ciolek - https://ciolek.dev
.