7.5High
CVE-2026-58210NATS Server: MQTT partial CONNECT packets can exhaust pre-auth memory
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.
Weakness (CWE):
CWE-400
Data: CVE.org, NVD, CISA KEV, FIRST EPSS, Ubuntu. Published as the sources state it, in English.
Affected products and versions
| Vendor | Product | Versions | |
|---|---|---|---|
| linuxfoundation | nats-server | < 2.12.12 | |
| nats-io | nats-server | < 2.12.12, >= 2.14.0-RC.1, < 2.14.3 |
References and patches
- https://github.com/nats-io/nats-server/security/advisories/GHSA-r72h-j7qq-v6qg Vendor Advisory
- https://github.com/nats-io/nats-server/commit/bce9ef39469e610aeddb819194ceb7f7edfc0861 Patch
- https://github.com/nats-io/nats-server/commit/e016e47bbf70304945f2ae9dc397e4862adefaf5 Patch
- https://github.com/nats-io/nats-server/releases/tag/v2.12.12 Release Notes
- https://github.com/nats-io/nats-server/releases/tag/v2.14.3 Release Notes
CPE matches (NVD) (2)
cpe:2.3:a:linuxfoundation:nats-server:*:*:*:*:*:*:*:*< 2.12.12cpe:2.3:a:linuxfoundation:nats-server:*:*:*:*:*:*:*:*≥ 2.14.0 < 2.14.3