The most severe Linux threat to surface in years catches the world flat-footed

Researchers publicly released exploit code for CVE-2026-31431, a Linux kernel local privilege-escalation flaw nicknamed CopyFail.

The bug can be used to gain root access across multiple major distributions, including Ubuntu 22.04, Amazon Linux 2023, SUSE 15.6, and Debian 12.

Theori had reported the issue privately, but the public release came before many vendors had shipped fixes.

Because the exploit is broadly applicable, it could enable container breakout and full compromise of servers, Kubernetes clusters, and CI/CD infrastructure.