High 7.5Published Jul 8, 2026

CVE-2026-58210NATS Server: MQTT partial CONNECT packets can exhaust pre-auth memory

Updated under an hour ago (Oct 26, 2026, 3:00 PM ET)

Does this affect you?

It affects nats-io nats-server and 1 other product. Add what you run to find out whether that includes you.

No exploitation reported and no EPSS estimate yet.

Do this next

Start free and add your stack

Free account, 1 product

Every CVE for nats-io nats-server

Exploited in the last 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.

CVSS: 7.5 HIGH (v3.1, CNA)CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Weakness (CWE): CWE-400
Known exploited: Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days): Not loaded for this CVE
Assigned by: GitHub_M
NVD analysis: Analyzed
Record last updated: Jul 9, 2026
First seen by InfoSec Signals: Oct 9, 2026

Affected products

Affected products

nats-io nats-server nats_io:nats_server (from the name)	before 2.12.12; from 2.14.0-RC.1, < 2.14.3	CNA record
linuxfoundation nats-server linuxfoundation:nats-server	before 2.12.12; from 2.14.0 before 2.14.3	NVD

References

References

https://github.com/nats-io/nats-server/security/advisories/GHSA-r72h-j7qq-v6qg	x-refsource-confirm, vendor-advisory
https://github.com/nats-io/nats-server/commit/bce9ef39469e610aeddb819194ceb7f7edfc0861	x-refsource-misc, patch
https://github.com/nats-io/nats-server/commit/e016e47bbf70304945f2ae9dc397e4862adefaf5	x-refsource-misc, patch
https://github.com/nats-io/nats-server/releases/tag/v2.12.12	x-refsource-misc, release-notes
https://github.com/nats-io/nats-server/releases/tag/v2.14.3	x-refsource-misc, release-notes

The CVE record on cve.org NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.