CVE-2026-102056 Juniper Networks CVE debrief

Who should care

Network administrators and security teams responsible for Junos OS and Junos OS Evolved installations should assess exposure and prioritize updates to prevent potential denial of service and information disclosure.

Why it matters

CVE-2026-102056 is a high-severity vulnerability in Junos OS and Junos OS Evolved that can cause denial of service and information disclosure. Network administrators and security teams should prioritize verifying and updating installations to prevent potential attacks.

• Denial of service due to daemon crash.
• Information disclosure through limited process memory exposure.
• Verification of Junos OS and Junos OS Evolved versions and configurations.
• Potential adjacent-network attack surface exposure.

Technical summary

The cfmd process in Junos OS and Junos OS Evolved is vulnerable to an Out-of-bounds Read attack, allowing an unauthenticated adjacent-network attacker to crash the daemon and disclose limited process memory. The vulnerability is caused by a specific CFM Message sent to a configured interface, and network administrators and security teams should prioritize verifying and updating installations to prevent potential denial of service and information disclosure. The affected products and components should be reviewed, and defensive measures should be implemented to prevent potential attacks.

Defensive priority

Network administrators and security teams should prioritize verifying and updating Junos OS and Junos OS Evolved installations to prevent potential denial of service and information disclosure.

Recommended defensive actions

• Verify and update Junos OS and Junos OS Evolved installations to the latest versions.
• Review network configurations to ensure Ethernet CFM is not enabled unnecessarily.
• Monitor system logs for potential CFM Message attacks.
• Implement additional security measures to detect and prevent adjacent-network attacks.
• Review compensating controls for exposed systems while remediation is scheduled and verified.
• 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 Program record and NVD vulnerability detail provide information on the Out-of-bounds Read vulnerability in Junos OS and Junos OS Evolved. The vendor advisory from Juniper Networks offers additional context.

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.