Juniper PFE DoS before 23.2R2 on MX/SRX routers
CVE-2026-57022 Published on July 9, 2026
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
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.
Vulnerability Analysis
CVE-2026-57022 is exploitable with network access, and does not require authorization privileges or user interaction. This vulnerability is consided to have a high level of attack complexity. The potential impact of an exploit of this vulnerability is considered to have no impact on confidentiality and integrity, and a high impact on availability.
Weakness Type
Improper Check for Unusual or Exceptional Conditions
The software does not check or incorrectly checks for unusual or exceptional conditions that are not expected to occur frequently during day to day operation of the software.
Products Associated with CVE-2026-57022
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Affected Versions
Juniper Networks Junos OS:- Before 23.2R2-S4 is affected.
- Version 23.4 and below 23.4R2-S5 is affected.
- Version 24.2 and below 24.2R2 is affected.