Injection Affecting github.com/nats-io/nats-server/v2/server package, versions <2.12.9>=2.14.0-RC.1 <2.14.1
Threat Intelligence
The probability is the direct output of the EPSS model, and conveys an overall sense of the threat of exploitation in the wild. The percentile measures the EPSS probability relative to all known EPSS scores. Note: This data is updated daily, relying on the latest available EPSS model version. Check out the EPSS documentation for more details.
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- published9 Jul 2026
- disclosed8 Jul 2026
- creditthesecguy45
Introduced: 8 Jul 2026
CVE-2026-58213 Â (opens in a new tab)How to fix?
Upgrade github.com/nats-io/nats-server/v2/server to version 2.12.9, 2.14.1 or higher.
Overview
github.com/nats-io/nats-server/v2/server is an A simple, secure and performant communications system for digital systems, services and devices.
Affected versions of this package are vulnerable to Injection in the MQTT SUBSCRIBE handling, which forwards protocol control characters from subscription filters into the NATS protocol stream sent to route and leaf node connections. A user with MQTT client access can inject arbitrary NATS protocol operations across route, gateway, or leaf node connections, reaching other cluster nodes or accounts, by placing protocol control characters in an MQTT subscription filter. Exploitation requires MQTT to be enabled and the server to have route, gateway, or leaf node connections that forward the corrupted stream, with anonymous MQTT deployments at higher risk.
Workaround
The anonymous-client attack surface can be reduced by disabling anonymous MQTT access where it is not required, though authenticated MQTT clients can still trigger the injection.