CVE-2026-58210CWE-400

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

High · published July 8, 2026

CVSS v3.1
7.5
EPSS
1%
Percentile
54.2
In the wild
Unconfirmed
What it is

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.

The record
Technical detail
CVSS v3.1
7.5 · HIGH
Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
CVSS v4.0
Not supplied
EPSS
0.00742 · 54.2th percentile
Weakness
CWE-400 · Uncontrolled Resource Consumption
Published
2026-07-08T20:13Z
EPSS history
Timeline
  • 08 JUL 20:13Z
    NATS Server: MQTT partial CONNECT packets can exhaust pre-auth memory
    cvelistv5