{"id":"UBUNTU-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":"2026-07-15T19:45:32.271859728Z","published":"2026-07-08T20:16:00Z","upstream":["CVE-2026-58253"],"references":[{"type":"REPORT","url":"https://ubuntu.com/security/CVE-2026-58253"},{"type":"REPORT","url":"https://www.cve.org/CVERecord?id=CVE-2026-58253"},{"type":"REPORT","url":"https://github.com/nats-io/nats-server/security/advisories/GHSA-38x3-76xf-cq45"}],"affected":[{"package":{"name":"nats-server","ecosystem":"Ubuntu:24.04:LTS","purl":"pkg:deb/ubuntu/nats-server?arch=source&distro=noble"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["2.9.19-1build1","2.10.3-1","2.10.4-1","2.10.7-1","2.10.7-1ubuntu0.1","2.10.7-1ubuntu0.2","2.10.7-1ubuntu0.3"],"ecosystem_specific":{"binaries":[{"binary_name":"golang-github-nats-io-nats-server-dev","binary_version":"2.10.7-1ubuntu0.3"},{"binary_version":"2.10.7-1ubuntu0.3","binary_name":"nats-server"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-58253.json"}},{"package":{"name":"nats-server","ecosystem":"Ubuntu:25.10","purl":"pkg:deb/ubuntu/nats-server?arch=source&distro=questing"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["2.10.24-1","2.10.27-1"],"ecosystem_specific":{"binaries":[{"binary_name":"golang-github-nats-io-nats-server-dev","binary_version":"2.10.27-1"},{"binary_version":"2.10.27-1","binary_name":"nats-server"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-58253.json"}},{"package":{"name":"nats-server","ecosystem":"Ubuntu:Pro:26.04:LTS","purl":"pkg:deb/ubuntu/nats-server?arch=source&distro=esm-apps%2Fresolute"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["2.10.27-1","2.10.27-1build1","2.10.27-1ubuntu0.26.04.1~esm1"],"ecosystem_specific":{"binaries":[{"binary_name":"golang-github-nats-io-nats-server-dev","binary_version":"2.10.27-1ubuntu0.26.04.1~esm1"},{"binary_name":"nats-server","binary_version":"2.10.27-1ubuntu0.26.04.1~esm1"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-58253.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:L/I:H/A:L"},{"type":"Ubuntu","score":"medium"}]}