Incorrect Initialization of Resource in Junos OS - CVE-2026-21913
Published: January 20, 2026
Vulnerability identifier: #VU121677
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-2026-21913
CWE-ID: CWE-1419
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote non-authenticated attacker to perform a denial of service (DoS) attack.
The vulnerability exists due to incorrect initialization of resource error in the Internal Device Manager (IDM). A remote non-authenticated attacker can cause a Denial-of-Service (DoS).
On EX4000 models with 48 ports (EX4000-48T, EX4000-48P, EX4000-48MP) a high volume of traffic destined to the device will cause an FXPC crash and restart, which leads to a complete service outage until the device has automatically restarted.
Affected software
Junos OS
How to mitigate CVE-2026-21913
Install updates from vendor's website.
Junos OS - addressed in versions 24.4R2, 25.2R1-S2, 25.2R2, 25.4R1