RUSTSEC-2026-0099
Name constraints were accepted for certificates asserting a wildcard name
Details
Permitted subtree name constraints for DNS names were accepted for certificates asserting a wildcard name.
This 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. This is very similar to [CVE-2025-61727](https://go.dev/issue/76442).
Since name constraints are restrictions on otherwise properly-issued certificates, this bug is reachable only after signature verification and requires misissuance to exploit.
This 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.
Are you affected?
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Affected packages
0.0.0-0 Fixed in: 0.103.12 Upgrade rustls-webpki to 0.103.12 or newer (ecosystem crates.io).