{"schema_version":"1.7.5","id":"GO-2026-4866","published":"2026-04-07T22:53:49Z","modified":"2026-09-09T10:41:44.857591646Z","aliases":["BIT-golang-2026-33810","CVE-2026-33810"],"related":["RHSA-2026:19135","RHSA-2026:19144","RHSA-2026:19353","RHSA-2026:19714","RHSA-2026:19719","RHSA-2026:19720","RHSA-2026:19721","RHSA-2026:28047","RHSA-2026:34192","RHSA-2026:34196","RHSA-2026:34197","RHSA-2026:34365","RHSA-2026:36796","RHSA-2026:39810","RHSA-2026:49702","RHSA-2026:49703","RHSA-2026:49712","RHSA-2026:51288","RHSA-2026:54757","RHSA-2026:56143","RHSA-2026:56223","RHSA-2026:57126","RHSA-2026:57649","RHSA-2026:59546","RHSA-2026:61253","RHSA-2026:61313","RHSA-2026:61907","RHSA-2026:62577","RHSA-2026:62578","RHSA-2026:63332","RHSA-2026:65359","RHSA-2026:65534","RHSA-2026:7291"],"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.","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"}}],"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"}],"database_specific":{"review_status":"REVIEWED","url":"https://pkg.go.dev/vuln/GO-2026-4866"},"credits":[{"name":"Riyas from Saintgits College of Engineering"},{"name":"k1rnt"},{"name":"@1seal"}]}