A Use After Free vulnerability in the packet forwarding engine (pfe) of Juniper Networks Junos OS on SRX Series allows an unauthenticated, network-based attacker to cause a Denial-of-Service (DoS).

When web filtering for TCP traffic is configured, a high volume of DNS requests increases the likelihood of a flowd crash and restart, which leads to a complete service outage until the service has automatically recovered. This is a race condition outside the attacker's direct control.

This issue affects Junos OS on SRX Series:

• All versions before 23.2R2-S5;
• from 23.4 before 23.4R2-S6;
• from 24.2 before 24.2R2-S3;
• from 24.4 before 24.4R2-S1;
• from 25.2 before 25.2R1-S1, 25.2R2.

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

This issue was seen during production usage.

This issue has been assigned CVE-2026-102078.

The following software releases have been updated to resolve this specific issue: Junos OS: 23.2R2-S5, 23.4R2-S6, 24.2R2-S3, 24.4R2-S1, 25.2R1-S1, 25.2R2, 25.4R1, and all subsequent releases.

This issue is being tracked as 1879966 which is visible on the Customer Support website.

Note: Juniper SIRT's policy is not to evaluate releases which are beyond End of Engineering (EOE) or End of Life (EOL).

There are no known workarounds for this issue.

2026-10-14: Initial Publication

• KB16613: Overview of the Juniper Networks SIRT Quarterly Security Bulletin Publication Process [juniper.net]
• KB16765: In which releases are vulnerabilities fixed? [juniper.net]
• KB16446: Common Vulnerability Scoring System (CVSS) and Juniper's Security Advisories [juniper.net]
• Report a Security Vulnerability - How to Contact the Juniper Networks Security Incident Response Team