CVE-2026-33810highCWE-1289

Case-sensitive excludedSubtrees name constraints cause Auth Bypass in crypto/x509

21Vexday Risk Score

No sign of exploitation. No public exploitation artifact known so far.

ssvc Trackcvss 7.5epss 0.3%

exploitation probability

0.3%top 72% of all CVEs

observed exploitation

nono source reports it

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.

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N

Affected products

Go standard library · crypto/x509

References