New RefluXFS Linux flaw lets attackers gain root privileges

A race condition vulnerability in the Linux kernel's XFS filesystem, dubbed RefluXFS and tracked as CVE-2026-64600, enables local attackers to gain root privileges by exploiting reflink functionality. The flaw, present since Linux kernel 4.11, allows overwriting of protected files such as /etc/passwd or SUID-root binaries without triggering kernel logs or losing the SUID bit, making detection difficult. Exploitation is reliable, persistent across reboots, and bypasses standard security mechanisms like SELinux and KASLR. Immediate kernel patching is advised, as no practical mitigations exist.

AI-extracted · verify before operational use