{"id":"GO-2026-4866","summary":"Case-sensitive excludedSubtrees name constraints cause Auth Bypass in crypto/x509","details":"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.\n\nThis only affects validation of otherwise trusted certificate chains, issued by a root CA in the VerifyOptions.Roots CertPool, or in the system certificate pool.","aliases":["CVE-2026-33810"],"modified":"2026-04-08T01:15:22.472258Z","published":"2026-04-07T22:53:49Z","database_specific":{"review_status":"REVIEWED","url":"https://pkg.go.dev/vuln/GO-2026-4866"},"references":[{"type":"FIX","url":"https://go.dev/cl/763763"},{"type":"REPORT","url":"https://go.dev/issue/78332"},{"type":"WEB","url":"https://groups.google.com/g/golang-announce/c/0uYbvbPZRWU"}],"affected":[{"package":{"name":"stdlib","ecosystem":"Go","purl":"pkg:golang/stdlib"},"ranges":[{"type":"SEMVER","events":[{"introduced":"1.26.0-0"},{"fixed":"1.26.2"}]}],"ecosystem_specific":{"imports":[{"path":"crypto/x509","symbols":["Certificate.Verify","dnsConstraints.query","newDNSConstraints"]}]},"database_specific":{"source":"https://vuln.go.dev/ID/GO-2026-4866.json"}}],"schema_version":"1.7.5","credits":[{"name":"Riyas from Saintgits College of Engineering"},{"name":"k1rnt"},{"name":"@1seal"}]}