Description
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.
Affected products
golang: go
References10
- pkg.go.dev/vuln/GO-2026-4866 Vendor Advisory
- go.dev/cl/763763 Patch
- go.dev/issue/78332 Issue Tracking
- groups.google.com/g/golang-announce/c/0uYbvbPZRWU Mailing ListRelease Notes
- www.openwall.com/lists/oss-security/2026/04/19/4
- www.openwall.com/lists/oss-security/2026/04/20/1
- access.redhat.com/errata/RHSA-2026:10155
- access.redhat.com/errata/RHSA-2026:10158
- access.redhat.com/errata/RHSA-2026:13545
- access.redhat.com/errata/RHSA-2026:14391
Metrics
- CVSS 3.1
-
8.2
HIGH
Score source: NVD
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:N - EPSS — exploit probability
- 0% percentile: 29 · as of 12 November 2026
- CWE
- CWE-295CWE-1289
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