SB2026070854 - Improper Check for Unusual or Exceptional Conditions in Junos OS

Security Bulletin ID SB2026070854

CSH Severity

Medium

Patch available

YES

Number of vulnerabilities 1

Exploitation vector Remote access

Highest impact Denial of service

Breakdown by Severity

Low
Medium
High
Critical

Description

This security bulletin contains information about 1 vulnerability.

1) Improper Check for Unusual or Exceptional Conditions (CVE-ID: CVE-2026-57022)

CWE-ID: CWE-754 - Improper Check for Unusual or Exceptional Conditions

CVSSv4: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Green

The vulnerability allows a remote non-authenticated attacker to perform a denial of service (DoS) attack.

The vulnerability exists due to improper check for unusual or exceptional conditions error in the Packet Forwarding Engine (PFE). A remote non-authenticated attacker can 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.

Remediation

Install update from vendor's website.

References

https://supportportal.juniper.net/s/article/2026-07-Security-Bulletin-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-CVE-2026-57022