wid-sec-w-2026-0858 · Published 2026-03-24 · View on BSI CERT-Bund ↗

NATS Server: Multiple Vulnerabilities

CVSS 8.6 HIGH

Risk Summary

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.

CVEs (11)

CVE-2026-33215 CVE-2026-33216 CVE-2026-33217 CVE-2026-33218 CVE-2026-33219 CVE-2026-33222 CVE-2026-33223 CVE-2026-33246 CVE-2026-33247 CVE-2026-33248 CVE-2026-33249

Affected Vendors

Open Source

Affected Products (4)

Open Source · NATS Server <2.12.6

Open Source · NATS Server 2.12.6

Open Source · NATS Server <2.11.15

Open Source · NATS Server 2.11.15

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