Configuration in nats-server - CVE-2021-32026
Published: May 4, 2021 / Updated: June 30, 2026
Vulnerability identifier: #VU135922
CSH Severity: Medium
CVSS v4: 6.9 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N]
CVE-ID: CVE-2021-32026
CWE-ID: CWE-16
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to negotiate unexpected TLS ciphersuites.
The vulnerability exists due to improper configuration handling in the TLS configuration logic when processing command-line TLS parameters. A remote attacker can initiate a TLS connection to negotiate unexpected TLS ciphersuites.
The issue occurs only when the server is started with TLS key and certificate settings supplied through command-line options.
Affected software
nats-server
How to mitigate CVE-2021-32026
Install security update from vendor's website.
nats-server - update to 2.2.3