High (7.5) in golang go. EPSS 0.4% chance of exploitation in the next 30 days. Fixed in stdlib 1.25.9, 1.26.2.
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.
Severity
CVSS 3.1
7.5 high
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
EPSS
0.4% chance of exploitation in the next 30 days; higher than 29% of CVEs (scores of 2026-10-31)