CVE-2026-101942 Juniper Networks CVE debrief

Who should care

Network administrators and security teams responsible for Junos OS and Junos OS Evolved configurations should assess exposure and prioritize remediation to prevent potential network instability. They should verify EVPN route signaling configurations and upgrade to fixed versions.

Why it matters

CVE-2026-101942 is a high-severity vulnerability in Junos OS and Junos OS Evolved that can cause a denial of service via a malformed EVPN route. Network administrators and security teams should prioritize verification of EVPN route signaling configurations and upgrade to fixed versions to prevent potential network instability.

• Denial of service via rpd process crash
• Potential network instability due to EVPN route signaling issues
• Need for verification of EVPN route signaling configurations
• Upgrade to fixed Junos OS and Junos OS Evolved versions

Technical summary

A vulnerability in the routing protocol daemon (rpd) process of Juniper Networks Junos OS and Junos OS Evolved allows an unauthenticated network-based attacker to cause a denial of service via a malformed EVPN Type-3 or Type-4 route received from a configured EVPN peer and processed during re-advertisement. The vulnerability is caused by an Improper Handling of Length Parameter Inconsistency. Affected product context includes Junos OS and Junos OS Evolved. Defensive impact includes potential network instability and denial of service.

Defensive priority

Network administrators and security teams should prioritize verification of EVPN route signaling configurations and upgrade to fixed Junos OS and Junos OS Evolved versions.

Recommended defensive actions

• Verify EVPN route signaling configurations for potential exposure
• Upgrade to fixed Junos OS and Junos OS Evolved versions
• Monitor network for unusual rpd process behavior
• 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 in Junos OS and Junos OS Evolved. Specific details on exploitation are limited, but defenders should verify EVPN route signaling configurations and upgrade to fixed versions to prevent potential network instability. The vulnerability affects Junos OS and Junos OS Evolved, and its severity is rated as HIGH. Evidence is based on CVE Program and NVD records.

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.