CVE-2026-33215 PUBLISHED

NATS is vulnerable to MQTT hijacking via Client ID

Assigner: GitHub_M
Reserved: 17.03.2026 Published: 24.03.2026 Updated: 25.03.2026

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.

Metrics

CVSS Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:L
CVSS Score: 6.5

Product Status

Vendor nats-io
Product nats-server
Versions
  • Version < 2.11.15 is affected
  • Version >= 2.12.0-RC.1, < 2.12.6 is affected

References

Problem Types

  • CWE-287: Improper Authentication CWE
  • CWE-488: Exposure of Data Element to Wrong Session CWE