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

Assigner: juniper
Reserved: 23.06.2026 Published: 09.07.2026 Updated: 10.07.2026

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.

Metrics

CVSS Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
CVSS Score: 5.9

Attack Vector	Network	Scope	Unchanged
Attack Complexity	High	Confidentiality Impact	None
Privileges Required	None	Integrity Impact	None
User Interaction	None	Availability Impact	High

CVSS 3.1

CVSS Vector: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:L/R:A/RE:M
CVSS Score: 8.2

Exploitability Metrics		Vulnerable System Impact Metrics		Subsequent System Impact Metrics
Attack Vector	Network	Confidentiality	None	Confidentiality	None
Attack Complexity	Low	Integrity	None	Integrity	None
Attack Requirements	Present	Availability	High	Availability	Low
Privileges Required	None
User Interaction	None

CVSS 4.0

Product Status

Vendor	Juniper Networks
Product	Junos OS
Versions	Default: unaffected affected from 0 to 23.2R2-S4 (excl.) affected from 23.4 to 23.4R2-S5 (excl.) affected from 24.2 to 24.2R2 (excl.)

Vendor

Juniper Networks

Product

Junos OS

Versions

Default: unaffected

affected from 0 to 23.2R2-S4 (excl.)
affected from 23.4 to 23.4R2-S5 (excl.)
affected from 24.2 to 24.2R2 (excl.)

Exploits

Juniper SIRT is not aware of any malicious exploitation of this vulnerability.

Workarounds

There are no known workarounds for this issue.

Solutions

The following software releases have been updated to resolve this specific issue: 22.4R3-S8, 23.2R2-S4, 23.4R2-S5, 24.2R2, 24.4R1, and all subsequent releases.

References

Problem Types

CWE-754 Improper Check for Unusual or Exceptional Conditions CWE

CVE-2026-57022 PUBLISHED