CVE intelligence and bounded remediation
CVE-2026-33215 — NATS-Server is a High-Performance server for NATS.io, a cloud and edge native messaging system
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.
- Severity
- Medium
- CVSS
- 6.5 (3.1)
- Published
- 2026-03-24
- CISA KEV
- Not currently listed
- Ecosystem
- software/application
- Weaknesses
- CWE-287, CWE-488
Affected products
- linuxfoundation / nats-server
Showing 1 representative product identities from 2 source matches. Confirm exact affected versions with the linked vendor and NVD evidence.
Matched remediation archetype
Authentication bypass and missing authentication
This catalog composition supplies bounded fallback guidance. Explicitly reviewed curated workflows load with the complete record below.
Check exposure
- Map every affected endpoint and protocol path, including alternate ports, legacy routes, recovery flows, service accounts, and machine-to-machine access.
- Confirm which deployments enable the affected authentication mode and whether the interface is reachable from untrusted networks.
- Review session, token, credential, and proxy trust configuration without attempting account takeover.
Remediate safely
- Apply the supported fix and centralize fail-closed authentication before protected request handling.
- Remove default or embedded credentials, rotate affected secrets and sessions, and bind authentication decisions to the intended audience and channel.
- Add negative tests for alternate routes, malformed or absent credentials, recovery flows, and proxy-derived identity.
Authoritative sources
Complete CVE record and remediation plan
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