CVE-2026-21913

Name of the Vulnerable Software and Affected Versions Juniper Networks Junos OS on EX4000-48T, EX4000-48P and EX4000-48MP versions prior to 24.4R2 Juniper Networks Junos OS on EX4000-48T, EX4000-48P and EX4000-48MP versions prior to 25.2R1-S2 Juniper Networks Junos OS on EX4000-48T, EX4000-48P and EX4000-48MP version 25.2R2

Description An incorrect initialization of resource issue in the Internal Device Manager (IDM) of Juniper Networks Junos OS on EX4000 models can allow an unauthenticated, network-based attacker to cause a Denial-of-Service (DoS). A high volume of traffic directed to the device can lead to an FXPC crash and restart, resulting in a complete service outage until the device automatically restarts. The reboot reason can be observed in the output of 'show chassis routing-engine' and as a log message, specifically: 'reason=0x4000002 reason string=0x4000002:watchdog + panic with core dump'.

Recommendations Juniper Networks Junos OS on EX4000-48T, EX4000-48P and EX4000-48MP versions prior to 24.4R2 should be upgraded to version 24.4R2 or later. Juniper Networks Junos OS on EX4000-48T, EX4000-48P and EX4000-48MP versions prior to 25.2R1-S2 should be upgraded to version 25.2R1-S2 or later. Juniper Networks Junos OS on EX4000-48T, EX4000-48P and EX4000-48MP version 25.2R2 is the fixed version.