CVE-2026-64139

A flaw was found in the ksmbd (kernel SMB daemon) component of the Linux kernel. A malicious or specially crafted file with a large number of POSIX Access Control List (ACL) entries can trigger a memory leak in the set_posix_acl_entries_dacl() function. This occurs when the accumulated DACL size overflows, causing struct smb_sid buffers to not be properly freed. An attacker can exploit this vulnerability to cause kernel memory exhaustion, leading to a Denial of Service (DoS) on the affected system.