Medium · published October 14, 2026
A NULL Pointer Dereference vulnerability in the DNS plugin of Juniper Networks Junos OS on SRX Series allows an unauthenticated, network-based attacker to cause a complete Denial-of-Service (DoS).
When multiple DNS queries are received in a single flow session, where one query matches a Security Intelligence (SecIntel) feed and another query is sent for DNS Domain Generation Algorithm (DGA) analysis, an error in processing logging of these asynchronous tasks can lead to an FPC crash. The exact timing conditions are outside an attacker's direct control.
This issue affects Junos OS on SRX Series:
* All versions before 23.2R2-S7.7;
* from 23.4 before 23.4R2-S8.13;
* from 24.2 before 24.2R2-S5.5;
* from 24.4 before 24.4R2-S4;
* from 25.2 before 25.2R2-S1;
* from 25.4 before 25.4R1-S2.