# CVE-2026-21913

## Summary

- **CVE ID:** CVE-2026-21913
- **Severity:** HIGH
- **CVSS Score:** 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:L/AU:Y/R:A/RE:M)
- **CWE:** CWE-1419
- **Published:** Jan 15, 2026
- **Last Modified:** Mar 12, 2026

## 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

- Juniper Networks — Junos OS (24.4)
- Juniper Networks — Junos OS (25.2)
- Juniper Networks — Junos OS (0)

## References

- [CNA](https://supportportal.juniper.net/JSA106014)
- [CNA](https://kb.juniper.net/JSA106014)

## Exploitation Prediction (EPSS)

- **EPSS Score:** 0.39%
- **EPSS Percentile:** 32.4

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_Exported from OnDuty AI Vulnerability Intelligence on 2026-09-11._