Linux Kernel Privilege Escalation Vulnerability (Dirty Frag) Alert

NSFOCUS warns of a Linux kernel local privilege escalation vulnerability called "Dirty Frag" (CVSS 7.8) that enables attackers to tamper with the page cache via esp4/esp6 (xfrm-ESP) and rxrpc modules to modify read-only files and gain root or escape containers; public PoCs exist, affected kernels include >=4.11 (esp) and >=6.5 (rxrpc), and mitigations include disabling the affected modules, applying official kernel updates when available, restricting user namespace/socket creation and monitoring critical files.