CVE-2026-29785

HIGH

NATS Server panic via malicious compression on leafnode port

Title source: cna
STIX 2.1

Description

NATS-Server is a High-Performance server for NATS.io, a cloud and edge native messaging system. Prior to versions 2.11.14 and 2.12.5, if the nats-server has the "leafnode" configuration enabled (not default), then anyone who can connect can crash the nats-server by triggering a panic. This happens pre-authentication and requires that compression be enabled (which it is, by default, when leafnodes are used). Versions 2.11.14 and 2.12.5 contain a fix. As a workaround, disable compression on the leafnode port.

References (3)

Scores

CVSS v3 7.5
EPSS 0.0013
EPSS Percentile 32.4%
Attack Vector NETWORK
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

CISA SSVC

Vulnrichment
Exploitation none
Automatable yes
Technical Impact partial

Details

CWE
CWE-476
Status published
Products (5)
linuxfoundation/nats-server < 2.11.14
nats-io/nats-server 0Go
nats-io/nats-server 0 - 2.11.14Go
nats-io/nats-server < 2.11.14
nats-io/nats-server >= 2.12.0-RC.1, < 2.12.5
Published Mar 25, 2026
Tracked Since Mar 26, 2026