This vulnerability is a Heap-based Buffer Overflow in the VXLAN Gateway Daemon (vgd) component of Juniper Networks Junos OS. The overflow can be triggered by a crafted OVSDB message and leads to a complete outage of the OVSDB control plane. In addition, the flaw can potentially allow an attacker to execute arbitrary code on the affected device, as indicated by the CWE-122 classification.

The issue affects Juniper Networks Junos OS devices running any release before the patched levels. Juniper has documented specific releases that contain the fix, including 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. All versions of Junos OS older than these are vulnerable.

The CVSS score of 8.7 indicates high severity, and the lack of an EPSS rating reflects limited publicly available exploitation data, though the potential for remote code execution remains concerning. The vulnerability is not listed in the CISA KEV catalog. Based on the description, the likely attack vector is an attacker or compromised SDN‑controller that can send malicious OVSDB messages to the vgd service, exploiting the buffer overflow to crash the service or execute code. The impact includes service disruption and, in worst cases, full control over the affected device.