CVE-2026-58210: Linuxfoundation Nats-Server

High severity, CVSS 7.5. EPSS: 0.7% chance of exploitation in the next 30 days.

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 products

• Linuxfoundation Nats-Server: before 2.12.12 (fixed in 2.12.12); from 2.14.0, before 2.14.3 (fixed in 2.14.3)

Published 2026-07-08. Last modified 2026-07-13.