CVE-2021-20226: Linux Kernel

High severity, CVSS 7.8. EPSS: 0.4% chance of exploitation in the next 30 days.

A use-after-free flaw was found in the io_uring in Linux kernel, where a local attacker with a user privilege could cause a denial of service problem on the system The issue results from the lack of validating the existence of an object prior to performing operations on the object by not incrementing the file reference counter while in use. The highest threat from this vulnerability is to data integrity, confidentiality and system availability.

Affected products

• Linux Linux Kernel: from 5.5, before 5.8.18 (fixed in 5.8.18); from 5.9.0, before 5.9.3 (fixed in 5.9.3)
• Netapp Cloud Backup: affected versions not specified

Published 2021-02-23. Last modified 2026-06-17.