CVE-2026-33810
HIGH severity · CVSS 8.2 · CWE-295
8.2CVSS HIGH
Summary
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.
Impact & exploitability
Attack vectorNetwork
Attack complexityLow
Privileges requiredNone
User interactionNone
Confidentiality impactHigh
Integrity impactLow
Availability impactNone
Exploit probability (EPSS)0%
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:N
Affected products we track (1)
Recommendation
Apply the vendor fix promptly. Open any affected product above for its exact safe version.
Official patch: https://go.dev/cl/763763 ↗
Additional information
- NVD record
- https://go.dev/cl/763763Patch
- https://pkg.go.dev/vuln/GO-2026-4866Advisory
- https://go.dev/issue/78332
- https://groups.google.com/g/golang-announce/c/0uYbvbPZRWU
- http://www.openwall.com/lists/oss-security/2026/04/19/4
- http://www.openwall.com/lists/oss-security/2026/04/20/1
- https://access.redhat.com/errata/RHSA-2026:10155
- https://access.redhat.com/errata/RHSA-2026:10158