NULL pointer dereference in nats-server - CVE-2020-26521
Published: June 29, 2022 / Updated: June 30, 2026
Vulnerability identifier: #VU64778
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-2020-26521
CWE-ID: CWE-476
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 a NULL pointer dereference error in JWT library in NATS nats-server. A remote attacker can pass specially crafted data and perform a denial of service (DoS) attack.
Affected software
nats-server
Fedora
nats-server
Fedora
nats-server
How to mitigate CVE-2020-26521
Install updates from vendor's website.
nats-server - update to 2.1.9
nats-server - update to 2.1.9-1.fc33
nats-server - update to 2.1.9-1.fc33