Input validation error in nats-server - CVE-2026-33218
Published: April 22, 2026
Vulnerability identifier: #VU126861
CSH Severity: Medium
CVSS v4: 8.7 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-33218
CWE-ID: CWE-20
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
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 in the leafnode port. A remote attacker can pass specially crafted input to the application and perform a denial of service (DoS) attack.
Affected software
nats-server
How to mitigate CVE-2026-33218
Install updates from vendor's website.
nats-server - addressed in versions 2.11.15, 2.12.6