Juniper Junos OS/Junos OS Evolved prior 24.4R1-S3-EVO Fileio Library out-of-bounds write

Summaryinfo

A vulnerability labeled as critical has been found in Juniper Junos OS and Junos OS Evolved. Impacted is an unknown function of the component Fileio Library. Executing a manipulation can lead to out-of-bounds write. This vulnerability appears as CVE-2026-57025. The attack may be performed from remote. There is no available exploit.

Detailsinfo

A vulnerability has been found in Juniper Junos OS and Junos OS Evolved and classified as critical. This vulnerability affects an unknown part of the component Fileio Library. The manipulation with an unknown input leads to a out-of-bounds write vulnerability. The CWE definition for the vulnerability is CWE-787. The product writes data past the end, or before the beginning, of the intended buffer. As an impact it is known to affect availability. CVE summarizes:

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' 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.

The advisory is available at supportportal.juniper.net. This vulnerability was named CVE-2026-57025 since 06/23/2026. The exploitation appears to be easy. The attack can be initiated remotely. Successful exploitation requires user interaction by the victim. The technical details are unknown and an exploit is not available. The structure of the vulnerability defines a possible price range of USD $0-$5k at the moment (estimation calculated on 07/10/2026).

Upgrading to version 23.2R2-S7, 23.4R2-S7, 23.4R2-S8-EVO, 24.2R2, 24.2R2-EVO, 24.4R1-S2 or 24.4R1-S3-EVO eliminates this vulnerability.

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Productinfo

Type

• Router Operating System

Vendor

• Juniper

Name

• Junos OS
• Junos OS Evolved

License

• commercial

Website

• Vendor: https://www.juniper.net/

CPE 2.3info

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Entryinfo

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