Juniper Junos OS up to 23.2R2-S3/23.4R2-S4/24.2R1 Packet Forwarding Engine denial of service

Summaryinfo

A vulnerability was found in Juniper Junos OS up to 23.2R2-S3/23.4R2-S4/24.2R1. It has been declared as critical. Affected by this issue is some unknown functionality of the component Packet Forwarding Engine. The manipulation results in denial of service. This vulnerability is cataloged as CVE-2026-57022. The attack may be launched remotely. There is no exploit available.

Detailsinfo

A vulnerability classified as critical has been found in Juniper Junos OS up to 23.2R2-S3/23.4R2-S4/24.2R1. Affected is some unknown processing of the component Packet Forwarding Engine. The manipulation with an unknown input leads to a denial of service vulnerability. CWE is classifying the issue as CWE-404. The product does not release or incorrectly releases a resource before it is made available for re-use. This is going to have an impact on availability. CVE summarizes:

An Improper Check for Unusual or Exceptional Conditions vulnerability in the Packet Forwarding Engine (PFE) of Juniper Networks Junos OS on MX with SPC3 and SRX Series allows an unauthenticated, network-based attacker to cause a Denial-of-Service (DoS). When an affected device initiates a TCP connection to an attacker-controlled system that responds with a specific packet, this causes a PFE crash and restart, which affects all services until the system has automatically recovered. This issue can happen among others in the following scenarios: ALG, SSL proxy, UTM, RTLOG, AppQoE probing, AAMW, ICAP, URL filtering. This issue affects Junos OS on MX Series with SPC3, SRX5k Series with SPC3, SRX1600 Series, SRX2300 Series, SRX4000 Series, and vSRX Series: * all versions before 23.2R2-S4, * 23.4 versions before 23.4R2-S5, * 24.2 versions before 24.2R2.

The advisory is available at supportportal.juniper.net. This vulnerability is traded as CVE-2026-57022 since 06/23/2026. The exploitability is told to be easy. It is possible to launch the attack remotely. The exploitation doesn't require any form of authentication. 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). This vulnerability is assigned to T1499 by the MITRE ATT&CK project.

Upgrading to version 23.2R2-S4, 23.4R2-S5 or 24.2R2 eliminates this vulnerability.

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Productinfo

Type

• Router Operating System

Vendor

• Juniper

Name

• Junos OS

Version

• 23.2R2-S3
• 23.4R2-S4
• 24.2R1

License

• commercial

Website

• Vendor: https://www.juniper.net/

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