CVE-2026-68457

A flaw was found in ksmbd in the Linux kernel. This vulnerability allows certain file system control (FSCTL) operations, specifically SET_SPARSE, SET_ZERO_DATA, and SET_COMPRESSION, to use incorrect credentials. Consequently, these operations can bypass the security checks established when the file was initially opened. This could enable a local attacker to perform unauthorized modifications to files, circumventing intended access restrictions.

This vulnerability is rated as an Important impact because improper credential handling during file system control requests allows unauthorized file tampering and integrity bypass on exposed SMB shares. In Red Hat Enterprise Linux, the in-kernel SMB server (ksmbd) is not compiled or supported in standard kernels, which rely on user-space Samba for network file sharing. Consequently, default Red Hat Enterprise Linux installations do not expose this vulnerable interface and are not affected.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.