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 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.

CVSS 3.1

7.5CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

EPSS

0.7% chance of exploitation in the next 30 days; higher than 54% of CVEs (scores of 2026-10-25)

CWE

CWE-400

Published

2026-07-08

Modified

2026-10-25

Record from

the NVD, synced 2026-10-25

Affected

• linuxfoundation:nats-server

References

• https://github.com/nats-io/nats-server/commit/bce9ef39469e610aeddb819194ceb7f7edfc0861
• https://github.com/nats-io/nats-server/commit/e016e47bbf70304945f2ae9dc397e4862adefaf5
• https://github.com/nats-io/nats-server/releases/tag/v2.12.12
• https://github.com/nats-io/nats-server/releases/tag/v2.14.3
• https://github.com/nats-io/nats-server/security/advisories/GHSA-r72h-j7qq-v6qg

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