Medium · published October 14, 2026
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.