Skip to content
OpenAdvisories
High · 7.5 CVE-2026-21913 EUVD-2026-2688GHSA-p84c-pfqc-c27p

Junos OS: EX4000: A high volume of traffic destined to the device leads to a crash and restart

Published Jan 15, 2026 · Updated Jan 15, 2026 · Assigned by juniper

Description

An Incorrect Initialization of Resource vulnerability in the Internal Device Manager (IDM) of Juniper Networks Junos OS on EX4000 models allows an unauthenticated, network-based attacker to 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.

The following reboot reason can be seen in the output of 'show chassis routing-engine' and as a log message:

  reason=0x4000002 reason_string=0x4000002:watchdog + panic with core dump

This issue affects Junos OS on EX4000-48T, EX4000-48P and EX4000-48MP:

* 24.4 versions before 24.4R2,
* 25.2 versions before 25.2R1-S2, 25.2R2.

This issue does not affect versions before 24.4R1 as the first Junos OS version for the EX4000 models was 24.4R1.

Affected products

VendorProductAffectedFixed
Juniper Networks Junos OS 24.4 – < 24.4R2, 25.2 – < 25.2R1-S2, 25.2R2 24.4R2

Advisories 2

References