CVE-2026-90176

A flaw was found in ksmbd, a server message block (SMB) protocol implementation within the Linux kernel. A logic error in the check_lock_range() function, which is responsible for enforcing file locks, causes it to bypass mandatory byte-range lock checks for single-byte operations. This allows an attacker to perform read, write, or truncate operations on a single byte within a file, even if that byte is protected by a conflicting lock. This could lead to unauthorized modification or access to data, potentially compromising data integrity.

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.