{"id":"JLSEC-2026-1126","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.","modified":"2026-08-03T19:15:03.810073652Z","published":"2026-08-03T19:08:57.739Z","upstream":["CVE-2026-33218"],"database_specific":{"license":"CC-BY-4.0","sources":[{"id":"CVE-2026-33218","imported":"2026-08-03T18:16:27.147Z","modified":"2026-08-03T13:17:53.330Z","published":"2026-03-25T20:16:32.623Z","url":"https://services.nvd.nist.gov/rest/json/cves/2.0?cveId=CVE-2026-33218","html_url":"https://nvd.nist.gov/vuln/detail/CVE-2026-33218","database_specific":{"status":"Modified"}}]},"references":[{"type":"WEB","url":"https://access.redhat.com/errata/RHSA-2026:21769"},{"type":"WEB","url":"https://access.redhat.com/errata/RHSA-2026:22347"},{"type":"WEB","url":"https://access.redhat.com/errata/RHSA-2026:23345"},{"type":"WEB","url":"https://access.redhat.com/security/cve/CVE-2026-33218"},{"type":"WEB","url":"https://advisories.nats.io/CVE/secnote-2026-10.txt"},{"type":"WEB","url":"https://bugzilla.redhat.com/show_bug.cgi?id=2451450"},{"type":"WEB","url":"https://github.com/nats-io/nats-server/security/advisories/GHSA-vprv-35vv-q339"},{"type":"WEB","url":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-33218.json"}],"affected":[{"package":{"name":"nats_server_jll","ecosystem":"Julia","purl":"pkg:julia/nats_server_jll?uuid=8b1691f7-6002-537d-bdf7-c6203599dc08"},"ranges":[{"type":"SEMVER","events":[{"introduced":"0"},{"fixed":"2.14.3+0"}]}],"database_specific":{"source":"https://github.com/JuliaLang/SecurityAdvisories.jl/tree/generated/osv/2026/JLSEC-2026-1126.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"}]}