RUSTSEC-2026-0099

    Dashboard / Vulnerabilities / RUSTSEC-2026-0099

    RUSTSEC-2026-0099

    Published: 14 Apr 2026Last Modified: 19 Sept 2026

    Summary: 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.

    References: https://crates.io/crates/rustls-webpki, https://rustsec.org/advisories/RUSTSEC-2026-0099.html

    Affected packages

    Package

    Name: rustls-webpki

    Purl: pkg:cargo/rustls-webpki

    Affected ranges

    Type: SEMVER

    Events:

    Introduced- 0.0.0-0
    Fixed -0.103.12

    Affected versions

    Common Vulnerability Scoring System

    Attack Vector
    Network
    Adjacent
    Local
    Physical
    Privileges Required
    None
    Low
    High
    User Interaction
    None
    Required
    Scope
    Unchanged
    Changed
    Confidentiality
    None
    Low
    High
    Integrity
    None
    Low
    High
    Availability
    None
    Low
    High