CVE-2026-93601
lowpriority · track · 9EPSS 0.002 · 10 %ileUSEPSS · scored 2026-10-27
rustls-webpki (the Rust webpki fork used by rustls) versions >= 0.101.0 and prior to 0.103.12 and 0.104.0-alpha.6 incorrectly accepted permitted-subtree DNS name constraints for certificates asserting a wildcard name. For example, a name constraint of accept.example.com was treated as satisfied by a certificate for *.example.com, which could feasibly assert reject.example.com — a name outside the permitted subtree. Because name constraints are restrictions applied to otherwise properly issued certificates, the issue is only reachable after signature verification succeeds and requires a misissued wildcard certificate to exploit.
cvss
Technical severity, 0–10. One row per scoring source.
base score 0–10 · higher = more severe · hover a vector to decode
ssvc
A stakeholder decision — act, attend, or track — from exploitation and impact.
weaknesses
The CWE weakness classes this flaw belongs to.
affected products (3)
Products and version ranges known to be affected.
advisories (2)
Vendor and ecosystem advisories describing this.
- GHSA-xgp8-3hg3-c2mhwebpki: Name constraints were accepted for certificates asserting a wildcard name2026-04-16ghsa · osvUS
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.
- RUSTSEC-2026-0099Name constraints were accepted for certificates asserting a wildcard name2026-04-14vendor · osvUS
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.
also known as (2)
Other names and identifiers for this entity.
- GHSA-xgp8-3hg3-c2mhosv
- RUSTSEC-2026-0099osv
sources
Which sources assert this record, and when.
references (2) nvd
External citations — patches, advisories, analysis.
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