NATS has MQTT plaintext password disclosure
21Vexday Risk Score
No sign of exploitation. No public exploitation artifact known so far.
ssvc Trackcvss 8.6epss 0.4%
exploitation probability
0.4%top 71% of all CVEs
observed exploitation
nono source reports it
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.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:N/A:N
Affected products
nats-io · nats-serverReferences
https://access.redhat.com/errata/RHSA-2026:21769https://access.redhat.com/errata/RHSA-2026:22347https://access.redhat.com/errata/RHSA-2026:23345https://access.redhat.com/security/cve/CVE-2026-33216https://advisories.nats.io/CVE/secnote-2026-05.txthttps://bugzilla.redhat.com/show_bug.cgi?id=2451448https://github.com/nats-io/nats-server/commit/b5b63cfc35a57075e09c1f57503d31721bed8099https://github.com/nats-io/nats-server/security/advisories/GHSA-v722-jcv5-w7mchttps://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-33216.json