Jack WallenHere we go again: Another Linux kernel vulnerability has been discovered that could grant standard users root privileges. The vulnerability, CVE-2026-64600 (nicknamed RefluXFS), hits any system using the XFS filesystem. The vulnerability was discovered by the Qualys Threat Research Unit as part of a research project using Anthropic's Claude Mythos Preview. Qualys first reported the vulnerability as "a race condition in the Linux kernel’s XFS filesystem copy-on-write path." The vulnerability has existed since kernel 4.11, and Qualys determined this was rated as an emergency priority because exploitation could happen using ordinary local privileges.