CVE-2026-102086: Junos OS: SRX Series: Multiple DNS queries processed by SecIntel and DGA in the same session cause a flowd crash
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.
Affected Software
Event History
Frequently Asked Questions
What traffic and configuration conditions are required for exploitation?
An unauthenticated network-based attacker must cause multiple DNS queries within one flow session. One query must match a SecIntel feed while another is submitted for DNS DGA analysis; the required timing is not directly controlled by the attacker.
Which Junos OS SRX releases contain the fix?
The issue is fixed in 23.2R2-S7.7, 23.4R2-S8.13, 24.2R2-S5.5, 24.4R2-S4, 25.2R2-S1, and 25.4R1-S2. Earlier affected releases should be upgraded to the applicable fixed release.