NULL pointer dereference in nats-server - CVE-2026-58250
Published: June 30, 2026
Vulnerability identifier: #VU135936
CSH Severity: High
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-2026-58250
CWE-ID: CWE-476
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to cause a denial of service.
The vulnerability exists due to a null pointer dereference in the leafnode handshake logic when processing repeated leafnode INFO protocol messages before authentication and account setup complete. A remote attacker can send repeated INFO messages to cause a denial of service.
Only leafnode listeners with compression enabled are vulnerable.
Affected software
nats-server
How to mitigate CVE-2026-58250
Install security update from vendor's website.
nats-server - addressed in versions 2.11.17, 2.12.8