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

Published Jul 9, 2026
·
Updated

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 Software

40 affected components
Juniper Networks Junos OS (Packet Forwarding Engine - PFE) on MX Series with SPC3<23.2R2-S4, >23.2R2-S4<23.4R2-S5, <24.2R2
All of the following
Any of the following
Juniper Junos<23.2
Juniper Junos=23.2
Juniper Junos=23.2-r1
Juniper Junos=23.2-r1-s1
Juniper Junos=23.2-r1-s2
Juniper Junos=23.2-r2
Juniper Junos=23.2-r2-s1
Juniper Junos=23.2-r2-s2
Juniper Junos=23.2-r2-s3
Juniper Junos=23.4
Juniper Junos=23.4-r1
Juniper Junos=23.4-r1-s1
Juniper Junos=23.4-r1-s2
Juniper Junos=23.4-r2
Juniper Junos=23.4-r2-s1
Juniper Junos=23.4-r2-s2
Juniper Junos=23.4-r2-s3
Juniper Junos=23.4-r2-s4
Juniper Junos=24.2
Juniper Junos=24.2-r1
Juniper Junos=24.2-r1-s1
Juniper Junos=24.2-r1-s2
Any of the following
Juniper vSRX
Juniper MX-SPC3
Juniper MX240
Juniper MX480
Juniper MX960
Juniper SRX1600
Juniper SRX2300
Juniper SRX4100
Juniper Srx4120
Juniper SRX4200
Juniper SRX4300
Juniper SRX4600
Juniper SRX4700
Juniper SRX5400
Juniper SRX5600
Juniper SRX5800
Juniper Srx5k-spc3

Remediation

Recommended actions to resolve this vulnerability, in priority order.

  1. Upgrade

    Upgrade Juniper Networks Junos OS (MX Series with SPC3; SRX Series with SPC3) to a version that resolves this vulnerability.

    Fixed in 22.4R3-S8
  2. Upgrade

    Upgrade Juniper Networks Junos OS (MX Series with SPC3; SRX Series with SPC3) to a version that resolves this vulnerability.

    Fixed in 23.2R2-S4
  3. Upgrade

    Upgrade Juniper Networks Junos OS (MX Series with SPC3; SRX Series with SPC3) to a version that resolves this vulnerability.

    Fixed in 23.4R2-S5
  4. Upgrade

    Upgrade Juniper Networks Junos OS (MX Series with SPC3; SRX Series with SPC3) to a version that resolves this vulnerability.

    Fixed in 24.2R2
  5. Upgrade

    Upgrade Juniper Networks Junos OS (MX Series with SPC3; SRX Series with SPC3) to a version that resolves this vulnerability.

    Fixed in 24.4R1

Event History

Jul 9, 2026
CVE Published
via MITRE·09:06 PM
Data Sourced
via MITRE·09:06 PM
RemedyDescriptionSeverityWeakness
Data Sourced
via NVD·10:17 PM
DescriptionSeverityWeaknessAffected Software
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Frequently Asked Questions

1

What is the severity of CVE-2026-57022?

The severity of CVE-2026-57022 is classified as high with a score of 8.2.

2

How do I fix CVE-2026-57022?

To mitigate CVE-2026-57022, apply the latest patches provided by Juniper Networks for the affected devices.

3

What impact does CVE-2026-57022 have on my network?

CVE-2026-57022 can allow an unauthenticated attacker to cause a Denial-of-Service (DoS), potentially impacting network availability.

4

Which devices are affected by CVE-2026-57022?

CVE-2026-57022 affects Juniper Networks Junos OS on MX Series with SPC3 and SRX Series devices.

5

What type of vulnerability is CVE-2026-57022?

CVE-2026-57022 is an Improper Check for Unusual or Exceptional Conditions vulnerability in the Packet Forwarding Engine.

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