Use-after-free in NanoMQ - CVE-2026-22040
Published: April 24, 2026
Vulnerability identifier: #VU127587
CSH Severity: Medium
CVSS v4.0: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:A/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Green
CVE-ID: CVE-2026-22040
CWE-ID: CWE-416
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vendor: NanoMQ
Affected software:
NanoMQ
NanoMQ
Detailed vulnerability description
The vulnerability allows a remote attacker to cause a denial of service.
The vulnerability exists due to use-after-free in the Broker process when handling a combined pattern of MQTT publish, reconnect, kick-out, and subscribe or unsubscribe operations using the same ClientID. A remote attacker can send valid MQTT control packets in a specially crafted traffic pattern to cause a denial of service.
User interaction is required, and the issue is generally reproducible under sustained high-frequency traffic conditions.
How to mitigate CVE-2026-22040
Install security update from vendor's website.