Buffer Overflow Vulnerability in Open vSwitch by Linux Kernel

CVE-2026-45840

What is CVE-2026-45840?

A vulnerability exists in Open vSwitch within the Linux kernel that can lead to a buffer overflow when a user with CAP_NET_ADMIN privileges attempts to set an excessively large PID array during vport mutations. This vulnerability allows the potential for kernel panics and system instability due to insufficient size checks on the allocated netlink reply buffers. Affected systems can be exploited under unprivileged user namespaces, leading to serious security implications.

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