Attackers are cashing in on fresh 'CopyFail' Linux flaw

CISA is warning that a newly-disclosed Linux kernel bug dubbed "CopyFail" is already being exploited, just days after researchers dropped a working root-level exploit. Tracked as CVE-2026-31431, the bug sits in the Linux kernel and gives low-level users a way to take full control of a system by modifying data they should only be able to read, effectively turning limited access into full root privileges on unpatched machines. The issue was disclosed by cybersecurity consultancy Theori, which said