High (8.2) in golang go. EPSS 0.3% chance of exploitation in the next 30 days. Fixed in stdlib 1.26.2.
When verifying a certificate chain containing excluded DNS constraints, these constraints are not correctly applied to wildcard DNS SANs which use a different case than the constraint. 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
8.2 high
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:N
EPSS
0.3% chance of exploitation in the next 30 days; higher than 27% of CVEs (scores of 2026-10-31)