CVE-2026-58213CWE-74

NATS Server: MQTT SUBSCRIBE Protocol Injection via Leaf Node/Route Forwarding allows arbitrary NATS command injection

High · published July 8, 2026

CVSS v3.1
7.1
EPSS
0%
Percentile
37.3
In the wild
Unconfirmed
What it is

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, corrupting the forwarded protocol stream and allowing injection of unintended NATS protocol operations. This issue is fixed in versions 2.14.1 and 2.12.9.

The record
Technical detail
CVSS v3.1
7.1 · HIGH
Vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:N
CVSS v4.0
Not supplied
EPSS
0.00441 · 37.3th percentile
Weakness
CWE-74 · Improper Neutralization of Special Elements in Output Used by a Downstream Component ('Injection')
Published
2026-07-08T19:52Z
EPSS history
Timeline
  • 08 JUL 19:52Z
    NATS Server: MQTT SUBSCRIBE Protocol Injection via Leaf Node/Route Forwarding allows arbitrary NATS command injection
    cvelistv5