Is CVE-2021-20226 actively exploited?

No active exploitation of CVE-2021-20226 has been confirmed so far. Continue monitoring, as exploit status can change.

Can CVE-2021-20226 be exploited remotely?

No. CVE-2021-20226 requires local access to exploit.

What is the CVSS score of CVE-2021-20226?

CVE-2021-20226 has a CVSS score of 7.8 (HIGH).

HOME VULNERABILITIESCVE-2021-20226

HIGH

CVE-2021-20226

CWE-416Published: February 23, 2021· Updated: Jun 17, 2026

7.8

CVSS v3.1

Official Description

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.

NVD Source

Technical Analysis

CVE-2021-20226 requires local access, meaning attackers must already have a foothold on the target system.

Exploitation requires low privileges, which limits the exposure to scenarios where an attacker has already gained initial access.

A successful exploit results in complete confidentiality breach (data exposure), full integrity compromise (data manipulation), availability disruption (denial of service), with a CVSS base score of 7.8.

From a weakness classification perspective (CWE-416): Use-after-free vulnerabilities involve accessing memory after it has been freed, often enabling arbitrary code execution.