GHSA-xgp8-3hg3-c2mh — rustls-webpki
LOWGHSA-xgp8-3hg3-c2mh is a low-severity (CVSS 2.2) CWE-295 vulnerability in rustls-webpki. A fix is available for rustls-webpki — see the affected versions and patch details below.
webpki: Name constraints were accepted for certificates asserting a wildcard name
Exploitation Status
No confirmed exploitation observed yet
- CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.
Exploitation and automatability from CISA’s SSVC triage for GHSA-xgp8-3hg3-c2mh.
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
How urgent is this, really
GHSA-xgp8-3hg3-c2mh plotted by exploitation likelihood (EPSS) against impact (CVSS). The shaded corner — EPSS 50%+ and CVSS 7.0+ — is where this CVE doesn't sit, though severity or exploitability alone can still warrant action.
Where this sits among everything scored
Of 377,166 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Real counts from FIRST.org, not a sample — log-scaled since the landscape is heavily right-skewed.
Real-World Exposure
rustls-webpki🦀rustls-webpkiReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects crates.io packages — download data is not available via public APIs for these ecosystems.
Description
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.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🦀crates.io | rustls-webpki | ≥ 0.101.0&&< 0.103.12 | 0.103.12cargo update -p rustls-webpki --precise 0.103.12 |
| 🦀crates.io | rustls-webpki | ≥ 0.104.0-alpha.1&&< 0.104.0-alpha.6 | 0.104.0-alpha.6cargo update -p rustls-webpki --precise 0.104.0-alpha.6 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for rustls-webpki, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update rustls-webpki to 0.103.12 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-xgp8-3hg3-c2mh is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like GHSA-xgp8-3hg3-c2mh can be triaged on real exposure rather than presence alone.
Tailored to GHSA-xgp8-3hg3-c2mh. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is GHSA-xgp8-3hg3-c2mh in your dependencies?
O3 Security finds GHSA-xgp8-3hg3-c2mh across crates.io dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.