CVE-2021-34458

Name: CVE-2021-34458
Creator: NVD / NIST
Published: 2021-07-16T21:15:09.883+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

CRITICALCVSS 9.9/10EPSS 2.50%

Last modified Jun 17, 2026

CVE-2021-34458 is a critical-severity vulnerability rated 9.9/10 on the CVSS scale. Windows Kernel Remote Code Execution Vulnerability. EPSS estimates a 2.50% chance of exploitation in the next 30 days.

Description

Windows Kernel Remote Code Execution Vulnerability

Metrics

CVSS 3.1

9.9/10

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H

EPSS Probability

2.50%

82.7th percentile

Probability of exploitation in the next 30 days. Learn more

Affected Software

Vendor	Product	Versions
Microsoft	Windows Server 2016	All versions
Microsoft	Windows Server 2016	20h2
Microsoft	Windows Server 2016	2004
Microsoft	Windows Server 2019	All versions

References

https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-34458Patch, Vendor Advisory
https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-34458Patch, Vendor Advisory

Timeline

Published: Jul 16, 2021
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2021-34458?

Windows Kernel Remote Code Execution Vulnerability

How severe is CVE-2021-34458?

CVE-2021-34458 has a CVSS score of 9.9/10 (CRITICAL severity). The EPSS model estimates a 2.50% probability of exploitation in the next 30 days.

How do I fix CVE-2021-34458?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2021-34458?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST