CVE-2026-58210 | NATS Server is a high-performance server for NATS.io, the cl… | CVSS 7.5 HIGH

Description

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.

Metadata

CVE ID: CVE-2026-58210
State: PUBLISHED
Assigner: GitHub_M
Reserved: 2026-06-29 17:09 UTC
Published: 2026-07-08 20:13 UTC
Last updated: 2026-07-08 20:13 UTC
Primary CWE: CWE-400
CWE-400: Uncontrolled Resource Consumption
Vendor / Product: nats-io / nats-server
Sources: cve.org · NVD

Severity & Metrics

7.5 HIGH CVSS 3.1

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

Affected products (1)

Vendor	Product	Platform	Versions
nats-io	nats-server	—	< 2.12.12, >= 2.14.0-RC.1, < 2.14.3

Weakness (CWE)

CWE	Source	Description
CWE-400	cna	CWE-400: Uncontrolled Resource Consumption

CVSS scores (1)

Score	Severity	Version	Source	Vector
7.5	HIGH	3.1	cna	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

References (5)

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