CVE-2026-33215CWE-287CWE-488

NATS is vulnerable to MQTT hijacking via Client ID

Medium · published March 24, 2026

CVSS v3.1
6.5
EPSS
0%
Percentile
20.7
In the wild
Unconfirmed
What it is

NATS-Server is a High-Performance server for NATS.io, a cloud and edge native messaging system. The nats-server provides an MQTT client interface. Prior to versions 2.11.15 and 2.12.5, Sessions and Messages can by hijacked via MQTT Client ID malfeasance. Versions 2.11.15 and 2.12.5 patch the issue. No known workarounds are available.

The record
Technical detail
CVSS v3.1
6.5 · MEDIUM
Vector
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:L
CVSS v4.0
Not supplied
EPSS
0.00292 · 20.7th percentile
Weaknesses
CWE-287 · Improper Authentication; CWE-488 · Exposure of Data Element to Wrong Session
Published
2026-03-24T20:55Z
EPSS history
Timeline
  • 24 MAR 20:55Z
    NATS is vulnerable to MQTT hijacking via Client ID
    cvelistv5