#VU123157 Input validation error in nats-server - CVE-2026-27571

 

#VU123157 Input validation error in nats-server - CVE-2026-27571

Published: February 24, 2026


Vulnerability identifier: #VU123157
Vulnerability risk: Medium
CVSSv4.0: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Green
CVE-ID: CVE-2026-27571
CWE-ID: CWE-20
Exploitation vector: Remote access
Exploit availability: No public exploit available
Vulnerable software:
nats-server
Software vendor:
NATS - The Cloud Native Messaging System

Description

The vulnerability allows a remote attacker to perform a denial of service (DoS) attack.

The vulnerability exists due to insufficient validation of user-supplied input when WebSockets handling the NATS messages. A remote attacker can use a compression bomb to cause excessive memory consumption and perform a denial of service (DoS) attack.


Remediation

Install updates from vendor's website.

External links