Linux Kernel Vulnerability in Netlink Binding Mechanism

CVE-2025-39926

What is CVE-2025-39926?

In the Linux kernel, a vulnerability in the netlink binding mechanism arose due to inadequate capability checks. Specifically, the genl_bind() function allowed bind() callbacks to be executed even when the necessary permissions were denied, indicated by a return value of -EPERM. This flaw could enable unauthorized users to inadvertently trigger callbacks intended for legitimate callers, leading to potential security breaches. The issue has been rectified by ensuring that bind() is only invoked after successful permission verification, thus safeguarding the kernel from such unauthorized access.

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