CVE-2026-103994 Juniper Networks CVE debrief

Who should care

Junos OS administrators, security teams, and network operators should review and apply Juniper Networks security patches, restrict access to OVSDB control plane, and monitor for suspicious SDN-controller activity. The vulnerability requires immediate attention from administrators and security teams.

Why it matters

CVE-2026-103994 is a high-severity vulnerability in Junos OS that requires immediate attention from administrators and security teams. The vulnerability allows a malicious or compromised SDN-controller to cause a complete outage of the OVSDB control plane and possibly remote code execution. Defenders should review and apply Juniper Networks security patches, restrict access to OVSDB control plane, and monitor for suspicious SDN-controller activity.

• Possible remote code execution
• Complete outage of OVSDB control plane
• Verification of Junos OS versions and patches required
• Restrict access to OVSDB control plane

Technical summary

A Heap-based Buffer Overflow vulnerability in the VXLAN Gateway Daemon (vgd) of Juniper Networks Junos OS allows a malicious or compromised SDN-controller to cause a complete outage of the OVSDB control plane and possibly remote code execution. The vulnerability requires immediate attention from administrators and security teams. The vulnerability allows a malicious or compromised SDN-controller to cause a complete outage of the OVSDB control plane and possibly remote code execution.

Defensive priority

High priority for Junos OS administrators and security teams

Recommended defensive actions

• Review and apply Juniper Networks security patches for Junos OS
• Restrict access to OVSDB control plane
• Monitor for suspicious SDN-controller activity

Evidence notes

The CVE record and source item provide details on the vulnerability, but limited information is available on exploitation or affected versions. The vulnerability is a Heap-based Buffer Overflow in the VXLAN Gateway Daemon (vgd) of Juniper Networks Junos OS. The CVE record was published on 2026-10-14T16:16:02.937Z and has not been modified since then. The source item provides details on the vulnerability, but limited information is available on exploitation or affected versions. The CVE

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.