Authentication Bypass by Spoofing in nats-server - CVE-2026-33223
Published: April 22, 2026
Vulnerability identifier: #VU126859
CSH Severity: Medium
CVSS v4.0: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N/E:U/U:Green
CVE-ID: CVE-2026-33223
CWE-ID: CWE-290
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vendor: NATS - The Cloud Native Messaging System
Affected software:
nats-server
nats-server
Detailed vulnerability description
The vulnerability allows a remote attacker to bypass authentication process.
The vulnerability exists due to incomplete stripping of Nats-Request-Info header. A remote user can spoof their identity to services which rely upon this header.
How to mitigate CVE-2026-33223
Install updates from vendor's website.