CVE-2026-58210

HIGH

NATS Server: MQTT partial CONNECT packets can exhaust pre-auth memory

Title source: cna
STIX 2.1

Description

NATS Server is a high-performance server for NATS.io, the cloud and edge native messaging system. Prior to 2.14.3 and 2.12.12, an unauthenticated MQTT client could cause the server to retain large incomplete MQTT CONNECT packets before authentication completed, consuming server memory while the parser waited for the advertised MQTT packet length. This issue is fixed in versions 2.14.3 and 2.12.12.

References (5)

Core 5

Scores

CVSS v3 7.5
EPSS 0.0073
EPSS Percentile 50.1%
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-400
Status published
Products (3)
linuxfoundation/nats-server < 2.12.12
nats-io/nats-server < 2.12.12
nats-io/nats-server >= 2.14.0-RC.1, < 2.14.3
Published Jul 08, 2026
Tracked Since Jul 09, 2026