CVE-2026-102078 Juniper Networks CVE debrief

Who should care

Network administrators and security teams responsible for Junos OS on SRX Series devices should assess exposure, prioritize remediation, and monitor for potential impacts. They should focus on version assessment and upgrade planning, as well as monitoring DNS traffic and flowd service status. Affected operators and platforms should review the supplied official advisory or CVE record to validate affected scope, severity, and vendor guidance.

Why it matters

CVE-2026-102078 is a medium-severity vulnerability in Junos OS on SRX Series devices, potentially causing DoS due to flowd crashes from high DNS traffic over TCP. Defenders should assess exposure, prioritize remediation, and monitor impacts.

• Potential Denial-of-Service (DoS) due to flowd crashes
• Service outage until automatic recovery
• Need for version assessment and upgrade planning
• Monitoring DNS traffic and flowd service status

Technical summary

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, leading to a complete service outage until the service has automatically recovered.

Defensive priority

Medium priority for Junos OS on SRX Series devices, focusing on version assessment and upgrade planning

Recommended defensive actions

• Assess Junos OS version exposure on SRX Series devices
• Prioritize upgrading to fixed versions for affected devices
• Monitor DNS traffic and flowd service status
• Review compensating controls for exposed systems while remediation is scheduled and verified
• Check relevant monitoring, detection, and logs for exposed assets that need extra review
• Track exceptions, retest remediated assets, and close the item only after evidence is documented
• Confirm whether affected product deployments exist in managed environments and assign an owner for follow-up

Evidence notes

The CVE record and source item provide details on the vulnerability and affected Junos OS versions. The vendor advisory is available for additional information. The vulnerability affects Junos OS on SRX Series devices, and defenders should verify the affected scope and vendor guidance. The evidence is limited to publicly available information, and further verification is recommended.

Sources and references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.