{"schema_version":"1.9.0","id":"CVE-2026-33218","published":"2026-03-25T19:53:12.075Z","modified":"2026-09-08T03:46:34.668363546Z","aliases":["BIT-nats-2026-33218","GHSA-vprv-35vv-q339","GO-2026-4837"],"related":["SUSE-SU-2026:1135-1","openSUSE-SU-2026:21483-1"],"summary":"NATS has pre-auth server panic via leafnode handling","details":"NATS-Server is a High-Performance server for NATS.io, a cloud and edge native messaging system. Prior to versions 2.11.15 and 2.12.6, a client which can connect to the leafnode port can crash the nats-server with a certain malformed message pre-authentication. Versions 2.11.15 and 2.12.6 contain a fix. As a workaround, disable leafnode support if not needed or restrict network connections to the leafnode port, if plausible without compromising the service offered.","affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/nats-io/nats-server","events":[{"introduced":"4dccf778573cd9a9e52fb8f119718459f6f2f761"},{"fixed":"0e0639058e0d2d8fce0cc34941f9897da152ab32"},{"introduced":"bef17e1d9de6574fae0eabe1798db0d4529834e4"},{"last_affected":"bef17e1d9de6574fae0eabe1798db0d4529834e4"}],"database_specific":{"extracted_events":[{"introduced":"2.12.0-RC.1"},{"fixed":"2.12.6"},{"introduced":"< < 2.11.15"},{"last_affected":"< < 2.11.15"}],"source":"AFFECTED_FIELD"}}],"versions":["< < 2.11.15","v2.11.15","v2.12.4","v2.12.5","v2.12.5-RC.2","v2.12.5-RC.1","v2.12.4-RC.6","v2.12.4-RC.5","v2.12.4-RC.4","v2.12.2","v2.12.4-RC.3","v2.12.4-RC.2","v2.12.4-RC.1","v2.12.3","v2.12.3-RC.5","v2.12.3-RC.4","v2.12.3-RC.3","v2.12.3-RC.2","v2.12.3-RC.1","v2.12.2-RC.4","v2.12.2-RC.3","v2.12.1","v2.12.2-RC.2","v2.12.2-RC.1","v2.12.0","v2.12.1-RC.5","v2.12.1-RC.4","v2.12.1-RC.3","v2.12.1-RC.2","v2.12.1-RC.1","v2.12.0-RC.6","v2.12.0-RC.5","v2.12.0-RC.4","v2.12.0-RC.3","v2.12.0-RC.2","v2.12.0-RC.1"],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-33218.json"}}],"references":[{"type":"WEB","url":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-33218.json"},{"type":"ADVISORY","url":"https://access.redhat.com/errata/RHSA-2026:21769"},{"type":"ADVISORY","url":"https://access.redhat.com/errata/RHSA-2026:22347"},{"type":"ADVISORY","url":"https://access.redhat.com/errata/RHSA-2026:23345"},{"type":"ADVISORY","url":"https://access.redhat.com/security/cve/CVE-2026-33218"},{"type":"ADVISORY","url":"https://advisories.nats.io/CVE/secnote-2026-10.txt"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/33xxx/CVE-2026-33218.json"},{"type":"ADVISORY","url":"https://github.com/nats-io/nats-server/security/advisories/GHSA-vprv-35vv-q339"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-33218"},{"type":"REPORT","url":"https://bugzilla.redhat.com/show_bug.cgi?id=2451450"}],"database_specific":{"cna_assigner":"GitHub_M","cwe_ids":["CWE-20"],"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/33xxx/CVE-2026-33218.json"},"severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"}]}