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.

To be exposed to this issue logging for SecIntel and/or DGA needs to be configured:
[ services security-metadata-streaming policy <name> dns detections <type> (fallback-options) notification log ]

[ services security-intelligence profile <name> rule <name> then log ]


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-2026-102086.

The following software releases have been updated to resolve this specific issue:

Junos OS: 23.2R2-S7.7, 23.4R2-S8.13, 24.2R2-S5.5, 24.4R2-S4, 25.2R2-S1, 25.4R1-S2, 26.2R1, and all subsequent releases.

Note: For Junos OS releases 23.2, 23.4, and 24.2, specific respins have been referenced. Previously published versions of these releases have been rebuilt to resolve the security vulnerabilities identified in this advisory.

This issue is being tracked as 1924805 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, but if not strictly required the logging should be turned off.

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