Slab-Out-Of-Bounds Read Vulnerability in Linux Kernel's ksmbd for Remote Clients

CVE-2026-64578

What is CVE-2026-64578?

A vulnerability exists in the ksmbd component of the Linux kernel that allows a remote client to exploit a flaw in the handling of compound SMB2 requests. Due to inadequate validation of the size of a compound request, the ksmbd_smb2_check_message function may read a two-byte field (StructureSize2) without confirming that the request contains sufficient data. As a result, this creates a risk of a slab-out-of-bounds read if the request is crafted with a specific size that bypasses normal checks. This security issue highlights the importance of robust input validation to prevent exploitation in shared environments.

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