Linux XFS has a decade-old race condition allowing full root access
Summary
A decade-old race condition vulnerability in the Linux XFS filesystem, known as RefluXFS (CVE-2026-64600), allows unprivileged local users to gain full root access. The flaw exploits a weakness in the reflink feature, enabling attackers to overwrite any readable file on an XFS volume.
IFF Assessment
This vulnerability allows for privilege escalation, which is bad news for defenders as it can lead to complete system compromise.
Severity
This vulnerability allows for Local Privilege Escalation (LPE) to root, a critical impact. Exploitation is described as highly reliable with no kernel log output, indicating high exploitability. The scope is effectively 'changed' as root access compromises the entire system.
Defender Context
This vulnerability in the widely used XFS filesystem presents a significant risk for Linux systems, especially those with the reflink feature enabled. Defenders should prioritize patching systems or disabling the reflink feature if it's not essential to mitigate the risk of local privilege escalation to root.