CVE-2026-103994

Junos OS: A crafted OVSDB message crashes vgd and allows remote code execution

Published Oct 14, 2026 CVSS 4.0 · 8.7 High EPSS < 1% KEV · Not listed
Description
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.

Remediation

Vendor Solution

The following software releases have been updated to resolve this specific issue: Junos OS: 23.2R2-S7.7, 23.4R2-S8.13, 24.2R2-S5.5, 24.4R2-S5, 25.2R2-S2, 25.4R1-S3, 25.4R2, 26.2R1-S2, 26.2R2, 26.4R1, and all subsequent releases. Note: For Junos OS releases 23.2, 23.4, and 24.2, specific respins have been referenced. Previously published versions of these releases have been rebuilt to resolve the security vulnerabilities identified in this advisory.


Vendor Workaround

There are no known workarounds for this issue.

Tracking

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Advisories

No advisories available
History
Type Values Removed Values Added
First Time appeared Juniper Networks
Juniper Networks junos Os
Vendors & Products Juniper Networks
Juniper Networks junos Os
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'total'}, 'version': '2.0.3'}

Type Values Removed Values Added
Description 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.
Title Junos OS: A crafted OVSDB message crashes vgd and allows remote code execution
Weaknesses CWE-122
References
Metrics cvssV3_1

{'score': 8.8, 'vector': 'CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H'}

cvssV4_0

{'score': 8.7, 'vector': 'CVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:L'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
juniper
Published
Updated
Oct 15, 2026, 3:57 AM
Reserved
Oct 1, 2026, 4:12 PM
Status
Awaiting Analysis
Published
Oct 14, 2026, 5:18 PM
Modified
Oct 15, 2026, 4:24 PM