CVE-2026-102078: CWE-416 Use After Free in Juniper Networks Junos OS

This vulnerability (CWE-416) exists in the packet forwarding engine (pfe) of Juniper Networks Junos OS on SRX Series. When web filtering for TCP traffic is configured, a high volume of DNS requests can trigger a race condition causing the flowd process to crash and restart. This leads to a complete service outage until the service recovers automatically. The issue affects all Junos OS versions before 23.2R2-S5, versions from 23.4 up to but not including 23.4R2-S6, versions from 24.2 up to but not including 24.2R2-S3, versions from 24.4 up to but not including 24.4R2-S1, and version 25.2 exactly. The vulnerability allows an unauthenticated attacker to cause a denial-of-service condition remotely.

An unauthenticated, network-based attacker can cause a denial-of-service by triggering a flowd crash and restart through a high volume of DNS requests when web filtering for TCP traffic is enabled. This results in a temporary service outage until the system automatically recovers. There is no impact on confidentiality or integrity, only availability is affected.

A patch is available for this vulnerability. Users should upgrade to fixed Junos OS versions 23.2R2-S5 or later, 23.4R2-S6 or later, 24.2R2-S3 or later, 24.4R2-S1 or later, or versions beyond 25.2R2 as applicable. Since this is a cloud service, Juniper manages remediation for hosted environments; for on-premises devices, apply the official patches promptly to mitigate the issue.