{"id":"DEBIAN-CVE-2026-58253","details":"NATS Server is a high-performance server for NATS.io, the cloud and edge native messaging system. Prior to 2.14.0, 2.12.7, and 2.11.16, when no_auth_user was configured, a parser fast path intended for ordinary client connections could also apply to route or leafnode listeners, allowing an unauthenticated peer to bypass inter-server CONNECT authentication and operate with the privileges associated with that connection type. This issue is fixed in versions 2.14.0, 2.12.7, and 2.11.16.","modified":"2026-09-14T17:03:21.227574241Z","published":"2026-07-08T20:16:54.943Z","upstream":["CVE-2026-58253"],"references":[{"type":"ADVISORY","url":"https://security-tracker.debian.org/tracker/CVE-2026-58253"}],"affected":[{"package":{"name":"nats-server","ecosystem":"Debian:12","purl":"pkg:deb/debian/nats-server?arch=source&distro=bookworm"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["2.10.1-1","2.10.16-1","2.10.18-1","2.10.24-1","2.10.27-1","2.10.3-1","2.10.4-1","2.10.7-1","2.12.4-1","2.12.6-1","2.14.1-1","2.14.3-1","2.14.6-1","2.9.10-1","2.9.19-1"],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-58253.json"}},{"package":{"name":"nats-server","ecosystem":"Debian:13","purl":"pkg:deb/debian/nats-server?arch=source&distro=trixie"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["2.10.27-1","2.12.4-1","2.12.6-1","2.14.1-1","2.14.3-1","2.14.6-1"],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-58253.json"}},{"package":{"name":"nats-server","ecosystem":"Debian:14","purl":"pkg:deb/debian/nats-server?arch=source&distro=forky"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"2.14.1-1"}]}],"versions":["2.10.27-1","2.12.4-1","2.12.6-1"],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-58253.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:L/I:H/A:L"}]}