CVE-2026-33218
NATS has pre-auth server panic via leafnode handling
CVSS Score
7.5
EPSS Score
0.1%
EPSS Percentile
31th
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.
| CWE | CWE-20 |
| Vendor | nats-io |
| Product | nats-server |
| Published | Mar 25, 2026 |
| Last Updated | Mar 26, 2026 |
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CVSS v3 Breakdown
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High
Affected Versions
nats-io / nats-server
< < 2.11.15 >= 2.12.0-RC.1, < 2.12.6