CVE-2026-58210: NATS Server is a high-performance server for NATS.io, the cloud and edge native messaging system. Prior to 2.14.3 and 2.12.12, an unauthenticated MQTT client…

PriorityP348high7.5CVSS 3.1

AVNACLPRNUINSUCNINAH

EPSS

0.74%

52.3th percentile

NATS Server is a high-performance server for NATS.io, the cloud and edge native messaging system. Prior to 2.14.3 and 2.12.12, an unauthenticated MQTT client could cause the server to retain large incomplete MQTT CONNECT packets before authentication completed, consuming server memory while the parser waited for the advertised MQTT packet length. This issue is fixed in versions 2.14.3 and 2.12.12.

Affected

4 ranges

Vendor	Product	Version range	Fixed in
linuxfoundation	nats-server	< 2.12.12	2.12.12
linuxfoundation	nats-server	>= 2.14.0 < 2.14.3	2.14.3
nats-io	nats-server	< 2.12.12	2.12.12
nats-io	nats-server	—	—

CVSS provenance

nvdv3.17.5HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

vendor_redhat7.5HIGH

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