CVE-2021-4154: Linux Kernel

High severity, CVSS 8.8. EPSS: 1.2% chance of exploitation in the next 30 days.

A use-after-free flaw was found in cgroup1_parse_param in kernel/cgroup/cgroup-v1.c in the Linux kernel's cgroup v1 parser. A local attacker with a user privilege could cause a privilege escalation by exploiting the fsconfig syscall parameter leading to a container breakout and a denial of service on the system.

Affected products

• Linux Linux Kernel: from 5.1, before 5.4.134 (fixed in 5.4.134); from 5.5, before 5.10.52 (fixed in 5.10.52); from 5.11, before 5.12.19 (fixed in 5.12.19); from 5.13, before 5.13.4 (fixed in 5.13.4); version 5.14 only
• Netapp Hci Baseboard Management Controller: version h300e only; version h300s only; version h410s only; version h500e only; version h500s only; version h700e only; …
• Red Hat Enterprise Linux: version 8.0 only
• Red Hat Virtualization: version 4.0 only

Published 2022-02-04. Last modified 2026-06-17.