CVE-2026-33218 — NATS has pre-auth server panic via leafnode handling
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 …
Published: 2026-03-25 · CVSS: 7.5 · CVSS 3.1
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.
Source: CVE Program · Revision 8b16575c39f1e1810c5e863010da073d2d3285e7