CVE-2026-58210
NATS Server is a high-performance server for NATS.io, the cloud and edge native messaging system.
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (0.74%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
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.
- CVSS 3.1
- 7.5 HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- EPSS
- 0.74% probability · 53th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-400
- Affected
- linuxfoundation/nats-server
- Source
- security-advisories@github.com
References
- https://github.com/nats-io/nats-server/commit/bce9ef39469e610aeddb819194ceb7f7edfc0861Patch
- https://github.com/nats-io/nats-server/commit/e016e47bbf70304945f2ae9dc397e4862adefaf5Patch
- https://github.com/nats-io/nats-server/releases/tag/v2.12.12Release Notes
- https://github.com/nats-io/nats-server/releases/tag/v2.14.3Release Notes
- https://github.com/nats-io/nats-server/security/advisories/GHSA-r72h-j7qq-v6qgVendor Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.