Vulnerability · Published Jul 9, 2026 · Assigned by juniper
CVE-2026-57022Junos 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
In plain English
A medium-severity security flaw in Junos OS from Juniper Networks. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.4% (higher than 35% of all known vulnerabilities).
Official 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 products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| Juniper Networks | Junos OS | 0 – before 23.2R2-S423.4 – before 23.4R2-S524.2 – before 24.2R2 |
Weakness: CWE-754 · Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
References
- https://supportportal.juniper.net/JSA110082 vendor-advisory