High

Nine-Year-Old RefluXFS Linux Flaw Gives Local Users Root on Default RHEL Installs

The Hacker News

July 23, 2026 at 8:04 AM

Overview

A newly disclosed vulnerability in the Linux kernel, known as RefluXFS and tracked as CVE-2026-64600, allows unprivileged local users to overwrite files owned by the root user on systems using the XFS filesystem. This flaw, which has been around for nine years, can grant persistent root access to attackers on default installations of Red Hat Enterprise Linux (RHEL), Fedora Server, and Amazon Linux. Researchers from Qualys demonstrated how this vulnerability can be exploited, raising significant concerns for system administrators and users of these platforms. Given the potential for local users to gain elevated privileges, it is crucial for affected organizations to assess their systems and apply necessary mitigations to prevent unauthorized access.

Key Takeaways

Affected Systems: Red Hat Enterprise Linux (RHEL), Fedora Server, Amazon Linux, XFS filesystem
Action Required: System administrators should apply available patches and updates for RHEL, Fedora Server, and Amazon Linux.
Timeline: Disclosed on July 22, 2023

Original Article Summary

RefluXFS, a new Linux kernel flaw disclosed on July 22 and tracked as CVE-2026-64600, lets an unprivileged local user overwrite root-owned files on an XFS filesystem and gain persistent root access. Qualys said default installations of Red Hat Enterprise Linux and its derivatives, Fedora Server, and Amazon Linux can meet the conditions for exploitation. The company demonstrated the race

Impact

Red Hat Enterprise Linux (RHEL), Fedora Server, Amazon Linux, XFS filesystem

Exploitation Status

No active exploitation has been reported at this time. However, organizations should still apply patches promptly as proof-of-concept code may exist.

Timeline

Disclosed on July 22, 2023

Remediation

System administrators should apply available patches and updates for RHEL, Fedora Server, and Amazon Linux. Additionally, users should review their system configurations to limit local user access and monitor for unusual file changes.

Additional Information

This threat intelligence is aggregated from trusted cybersecurity sources. For the most up-to-date information, technical details, and official vendor guidance, please refer to the original article linked below.

Related Topics: This incident relates to Linux, CVE, Vulnerability, and 2 more.

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