{"id":"UBUNTU-CVE-2026-93601","details":"rustls-webpki (the Rust webpki fork used by rustls) versions \u003e= 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.","modified":"2026-09-21T21:40:59.256739492Z","published":"2026-09-21T00:00:00Z","upstream":["CVE-2026-93601"],"references":[{"type":"REPORT","url":"https://ubuntu.com/security/CVE-2026-93601"},{"type":"REPORT","url":"https://www.cve.org/CVERecord?id=CVE-2026-93601"},{"type":"REPORT","url":"https://github.com/rustls/webpki/security/advisories/GHSA-xgp8-3hg3-c2mh"},{"type":"REPORT","url":"https://www.vulncheck.com/advisories/rustls-webpki-0.101.0-before-0.103.12-name-constraint-bypass"}],"affected":[{"package":{"name":"rust-rustls-webpki","ecosystem":"Ubuntu:24.04:LTS","purl":"pkg:deb/ubuntu/rust-rustls-webpki?arch=source&distro=noble"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["0.101.4-4","0.101.7-2.1"],"ecosystem_specific":{"binaries":[{"binary_name":"librust-rustls-webpki-dev","binary_version":"0.101.7-2.1"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-93601.json"}},{"package":{"name":"rust-rustls-webpki","ecosystem":"Ubuntu:26.04:LTS","purl":"pkg:deb/ubuntu/rust-rustls-webpki?arch=source&distro=resolute"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["0.102.8-5","0.103.7-1","0.103.7-1build1","0.103.9+ds-1","0.103.9+ds-2"],"ecosystem_specific":{"binaries":[{"binary_name":"librust-rustls-webpki-dev","binary_version":"0.103.9+ds-2"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-93601.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:N/I:L/A:N"},{"type":"CVSS_V4","score":"CVSS:4.0/AV:N/AC:H/AT:P/PR:H/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N"},{"type":"Ubuntu","score":"medium"}]}