CVE-2026-57025

/// Technical description

A Return of Pointer Value Outside of Expected Range vulnerability in the fileio library of Juniper Networks Junos OS and Junos OS Evolved allows a local, low-privilged attacker to cause a Denial-of-Service (DoS).

On EX Series, QFX Series and MX Series a low-privileged attacker issuing a specific 'show l2-learning' or 'show ethernet-switching' command will cause an l2ald crash which will lead to a temporary service impact for all layer 2 services until the process has automatically restarted.

This issue affects EX Series, QFX Series, MX Series:

Junos OS:

* all versions before 23.2R2-S7,

* 23.4 versions before 23.4R2-S7,

* 24.2 versions before 24.2R2,

* 24.4 versions before 24.4R1-S2.

Junos OS Evolved:

* all versions before 23.2R2-S7-EVO,

* 23.4 versions before 23.4R2-S8-EVO,

* 24.2 versions before 24.2R2-EVO,

* 24.4 versions before 24.4R1-S3-EVO.

/// Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

/// References