Copy Fail: New Linux bug enables Root via page‑cache corruption

Security Affairs

April 30, 2026 at 6:23 PM

Linux CVE Vulnerability Privilege Escalation

Overview

A newly discovered vulnerability in Linux, tracked as CVE-2026-31431 and named 'Copy Fail', could allow local, unprivileged users to escalate their privileges to root. This flaw lets attackers write four controlled bytes into page cache files, which is a significant security risk for many major Linux distributions. Researchers from Xint Code assigned a CVSS score of 7.8 to this vulnerability, indicating its seriousness. The issue affects various Linux systems, potentially putting numerous users at risk if they do not take action. Companies and users are urged to monitor their systems and apply necessary patches to mitigate this risk.

Key Takeaways

Affected Systems: Major Linux distributions including Ubuntu, Debian, Fedora, CentOS, and others that utilize the affected page cache mechanism.
Action Required: Users should apply security patches as soon as they are released by their respective Linux distribution maintainers.
Timeline: Newly disclosed

Original Article Summary

Linux flaw CVE‑2026‑31431, ‘Copy Fail,’ lets any local user write four bytes into page cache files, enabling easy escalation to root on major distros. Xint Code researchers warn of a serious Linux flaw, tracked as CVE-2026-31431 (CVSS score of 7.8), dubbed Copy Fail. It lets any local, unprivileged user write four controlled bytes into the […]

Impact

Major Linux distributions including Ubuntu, Debian, Fedora, CentOS, and others that utilize the affected page cache mechanism.

Exploitation Status

The exploitation status is currently unknown. Monitor vendor advisories and security bulletins for updates.

Timeline

Newly disclosed

Remediation

Users should apply security patches as soon as they are released by their respective Linux distribution maintainers. It is advisable to monitor official channels for updates and to consider restricting local user access until a patch is applied.

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 1 more.

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