Summary
webpki: Name constraints were accepted for certificates asserting a wildcard name
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.
Since name constraints are restrictions on otherwise properly-issued certificates, this bug is reachable only after signature verification and requires misissuance to exploit.
Impact
GHSA-XGP8-3HG3-C2MH has a CVSS score of 2.2 (Low). The vector is network-reachable, high privileges required, and no user interaction. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (0.103.12, 0.104.0-alpha.6); upgrading removes the vulnerable code path.
Affected versions
Security releases
Kodem intelligence
Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.
Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter. Kodem's runtime-powered SCA identifies whether this CVE is reachable in your applications.
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rustls-webpki to 0.103.12 or later; rustls-webpki to 0.104.0-alpha.6 or later
Kodem Kai can prioritize this vulnerability in your dependency tree and generate a fix recommendation.
Frequently Asked Questions
- What is GHSA-XGP8-3HG3-C2MH? GHSA-XGP8-3HG3-C2MH is a low-severity security vulnerability in rustls-webpki (rust), affecting versions >= 0.101.0, < 0.103.12. It is fixed in 0.103.12, 0.104.0-alpha.6.
- How severe is GHSA-XGP8-3HG3-C2MH? GHSA-XGP8-3HG3-C2MH has a CVSS score of 2.2 (Low). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
- Which versions of rustls-webpki are affected by GHSA-XGP8-3HG3-C2MH? rustls-webpki (rust) versions >= 0.101.0, < 0.103.12 is affected.
- Is there a fix for GHSA-XGP8-3HG3-C2MH? Yes. GHSA-XGP8-3HG3-C2MH is fixed in 0.103.12, 0.104.0-alpha.6. Upgrade to this version or later.
- Is GHSA-XGP8-3HG3-C2MH exploitable, and should I be worried? Whether GHSA-XGP8-3HG3-C2MH is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
- What actually determines whether GHSA-XGP8-3HG3-C2MH is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
- How do I fix GHSA-XGP8-3HG3-C2MH?
- Upgrade
rustls-webpkito 0.103.12 or later - Upgrade
rustls-webpkito 0.104.0-alpha.6 or later
- Upgrade