Linux Kernel SMB1 Client Vulnerability with CIFS UNIX Mounts

CVE-2026-31710

What is CVE-2026-31710?

A vulnerability in the Linux kernel's SMB1 client affects UNIX mounts where improper handling of CIFS flags can lead to incorrect directory separators in paths. The issue arises when cifs_mount_get_tcon() is called without properly resetting the UNIX capabilities, resulting in the loss of important flags like CIFS_MOUNT_POSIXACL and CIFS_MOUNT_POSIX_PATHS. This can cause significant problems in file path resolutions, impacting data integrity and system functionality.

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