CVE-2026-57022

Junos OS: MX Series with SPC3, SRX Series: Specific packet in response to a TCP connection establishment by the affected device can crash the PFE

MEDIUM

5.9

CVSS Score

Published: July 9, 2026 at 09:06 PM UTC

Updated: October 25, 2026 at 03:10 PM UTC

1 product affected across 1 vendorJunos· also runs on 17 platforms

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Severity

MEDIUM5.9

Exploit prediction

EPSS 0.4%

SSVC

No known exploit

Description

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.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

Junos · Juniper Networks

95%

v < 23.223.2 23.2 r1 23.2 r1-s1 23.2 r1-s2 23.2 r2 23.2 r2-s1 23.2 r2-s2 23.2 r2-s3 23.4 23.4 r1 23.4 r1-s1 23.4 r1-s2 23.4 r2 23.4 r2-s1 23.4 r2-s2 23.4 r2-s3 23.4 r2-s4 24.2 24.2 r1 24.2 r1-s1 24.2 r1-s2

Affected range stops below 23.2, so it looks safe — our inference, not a vendor statement

Affected range stops below 23.2R2-S4, so it looks safe — our inference, not a vendor statement

Affected range stops below 23.4R2-S5, so it looks safe — our inference, not a vendor statement

Affected range stops below 24.2R2, so it looks safe — our inference, not a vendor statement

juniper-mx-spc3 (environment) · juniper-mx240 (environment) · juniper-mx480 (environment) · juniper-mx960 (environment) · juniper-srx1600 (environment) · juniper-srx2300 (environment) · juniper-srx4100 (environment) · juniper-srx4120 (environment) · juniper-srx4200 (environment) · juniper-srx4300 (environment) · juniper-srx4600 (environment) · juniper-srx4700 (environment) · juniper-srx5400 (environment) · juniper-srx5600 (environment) · juniper-srx5800 (environment) · juniper-srx5k-spc3 (environment) · juniper-vsrx (environment)