What’s Vulnerable › Vulnerabilities

CVE-2026-32281: Inefficient policy validation in crypto/x509

• Severity: high (CVSS 7.5 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.4% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-04-08 · updated 2026-07-25
• Weakness: CWE-295

Description

Validating certificate chains which use policies is unexpectedly inefficient when certificates in the chain contain a very large number of policy mappings, possibly causing denial of service. This only affects validation of otherwise trusted certificate chains, issued by a root CA in the VerifyOptions.Roots CertPool, or in the system certificate pool.

Affected products

• Go: before 1.25.9; from 1.26.0 before 1.26.2 — fixed in 1.25.9, 1.26.2
• Go Stdlib: before 1.25.9; from 1.26.0-0 before 1.26.2 — fixed in 1.25.9, 1.26.2

How to fix

Upgrade to a fixed version: Go 1.25.9, 1.26.2; Go Stdlib 1.25.9, 1.26.2. Check the vendor advisory for mitigations.

References

• https://go.dev/cl/758061
• https://go.dev/issue/78281
• https://groups.google.com/g/golang-announce/c/0uYbvbPZRWU
• https://pkg.go.dev/vuln/GO-2026-4946

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