{"id":"RUSTSEC-2026-0099","aliases":["GHSA-xgp8-3hg3-c2mh"],"title":"Name constraints were accepted for certificates asserting a wildcard name","summary":"Name constraints were accepted for certificates asserting a wildcard name","severity":"none","vendor":"rustls-webpki","product":"rustls-webpki","ecosystem":"rust","affected":["rustls-webpki >= 0.104.0-alpha.1, < 0.104.0-alpha.6"],"patched":["rustls-webpki 0.104.0-alpha.6"],"published":"2026-04-14","updated":"2026-07-17","source":"OSV","sourceUrl":"https://osv.dev/vulnerability/RUSTSEC-2026-0099","references":[{"url":"https://crates.io/crates/rustls-webpki"},{"url":"https://rustsec.org/advisories/RUSTSEC-2026-0099.html"}],"tags":["osv","rust"],"ingestedAt":"2026-07-17T19:00:51.966Z","slug":"RUSTSEC-2026-0099","body":"## Overview\n\nPermitted subtree name constraints for DNS names were accepted for certificates asserting a wildcard name.\n\nThis was incorrect because, given a name constraint of `accept.example.com`, `*.example.com` could feasibly allow a name of `reject.example.com` which is outside the constraint.\nThis is very similar to [CVE-2025-61727](https://go.dev/issue/76442).\n\nSince name constraints are restrictions on otherwise properly-issued certificates, this bug is reachable only after signature verification and requires misissuance to exploit.\n\nThis vulnerability is identified as [GHSA-xgp8-3hg3-c2mh](https://github.com/rustls/webpki/security/advisories/GHSA-xgp8-3hg3-c2mh). Thank you to [@1seal](https://github.com/1seal) for the report.\n\n## Affected packages\n\n- `rustls-webpki >= 0.104.0-alpha.1, < 0.104.0-alpha.6`\n\n## Remediation\n\nUpgrade to a patched release:\n\n- `rustls-webpki 0.104.0-alpha.6`","depth":"sunlit","depthScore":3,"depthScoreParts":{"impact":2.8,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}