NATS-Server is a High-Performance server for NATS.io, a cloud and edge native messaging system. Prior to versions 2.11.15 and 2.12.6, for MQTT deployments using usercodes/passwords: MQTT passwords are incorrectly classified as a non-authenticating identity statement (JWT) and exposed via monitoring endpoints. Versions 2.11.14 and 2.12.6 contain a fix.
As a workaround, ensure monitoring end-points are adequately secured. Best practice remains to not expose the monitoring endpoint to the Internet or other untrusted network users.
Attack Parameters
Attack Vector
Network
Can be exploited remotely
Attack Complexity
Low
Easy to exploit
Privileges Required
None
No privileges needed
User Interaction
None
No user interaction needed
Impact Assessment
Confidentiality
High
Complete data leak
Integrity
None
No data modification
Availability
None
No disruption
CVSS Vector v3.1
Weakness Type (CWE)
Vulnerable Products 2
| Configuration | From (including) | Up to (excluding) |
|---|---|---|
|
Linuxfoundation Nats-Server
cpe:2.3:a:linuxfoundation:nats-server:*:*:*:*:*:*:*:*
|
— |
2.11.15
|
|
Linuxfoundation Nats-Server
cpe:2.3:a:linuxfoundation:nats-server:*:*:*:*:*:*:*:*
|
2.12.0
|
2.12.6
|
References 3
https://advisories.nats.io/CVE/secnote-2026-05.txt
security-advisories@github.com
https://github.com/nats-io/nats-server/commit/b5b63cfc35a57075e09c1f57503d31721…
security-advisories@github.com
https://github.com/nats-io/nats-server/security/advisories/GHSA-v722-jcv5-w7mc
security-advisories@github.com