CVE-2026-58213: Improper Neutralization of Special Elements in Output Used by a Downstream Component

NATS Server is a high-performance server for NATS.io, the cloud and edge native messaging system. Prior to 2.14.1 and 2.12.9, an MQTT client could include protocol control characters in subscription filters that were later forwarded as NATS protocol data to route or leafnode connections, corrupti...

nats-server: NATS Server: Protocol stream corruption and unintended operation injection via MQTT client subscription filters

A flaw was found in NATS Server. An authenticated MQTT client could exploit this by embedding protocol control characters within subscription filters. These characters would then be forwarded as NATS protocol data to route or leafnode connections, leading to the corruption of the protocol stream...

nats-server: NATS Server: Protocol stream corruption and unintended operation injection via MQTT client subscription filters

A flaw was found in NATS Server. An authenticated MQTT client could exploit this by embedding protocol control characters within subscription filters. These characters would then be forwarded as NATS protocol data to route or leafnode connections, leading to the corruption of the protocol stream...