CVE-2026-102035 Juniper Networks CVE debrief

Who should care

Network administrators and security teams responsible for managing Junos OS and Junos OS Evolved devices should assess exposure and prioritize patching to prevent potential denial-of-service attacks.

Why it matters

CVE-2026-102035 is a medium-severity vulnerability in Junos OS and Junos OS Evolved that allows an adjacent attacker to cause a denial of service. Network administrators and security teams should prioritize verifying and applying vendor patches to prevent potential denial-of-service attacks.

• Denial-of-service attacks may occur if the vulnerability is exploited
• Verification of vendor patches and network configurations is necessary to prevent exploitation
• Network administrators and security teams should prioritize patching to prevent potential attacks

Technical summary

A Reachable Assertion vulnerability in the l2ald process of Juniper Networks Junos OS and Junos OS Evolved allows an adjacent attacker to cause a denial of service via an ICCP peer message when MC-LAG IRB MAC synchronization is enabled. The vulnerability affects Junos OS and Junos OS Evolved, specifically impacting configurations where MC-LAG IRB MAC synchronization is enabled. The l2ald process fails to properly handle certain ICCP peer messages, leading to a denial-of-service condition. Juniper Networks has released patches to address this vulnerability, and

Defensive priority

Network administrators and security teams should prioritize verifying and applying vendor patches to prevent potential denial-of-service attacks.

Recommended defensive actions

• Verify and apply vendor patches for Junos OS and Junos OS Evolved
• Review and update network configurations to prevent exploitation
• Monitor network devices for potential denial-of-service attacks

Evidence notes

The CVE record and source item provide details on a Reachable Assertion vulnerability in Junos OS and Junos OS Evolved, which allows an adjacent attacker to cause a denial of service via an ICCP peer message when MC-LAG IRB MAC synchronization is enabled.

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.