New Linux 'Copy Fail' Vulnerability Enables Root Access on Major Distributions

Cybersecurity researchers have disclosed details of a Linux local privilege escalation (LPE) flaw that could allow an unprivileged local user to obtain root. The high-severity vulnerability tracked as CVE-2026-31431 (CVSS score: 7.8) has been codenamed Copy Fail by Xint.io and Theori. "An unprivileged local user can write four controlled bytes into the page cache of any readable file on a Linux