CVE-2021-34503

Name: CVE-2021-34503
Creator: NVD / NIST
Published: 2021-07-14T18:15:11.767+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

HIGHCVSS 7.8/10EPSS 2.11%

Last modified Jun 17, 2026

CVE-2021-34503 is a high-severity vulnerability rated 7.8/10 on the CVSS scale. Microsoft Windows Media Foundation Remote Code Execution Vulnerability. EPSS estimates a 2.11% chance of exploitation in the next 30 days.

Description

Microsoft Windows Media Foundation Remote Code Execution Vulnerability

Metrics

CVSS 3.1

7.8/10

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

EPSS Probability

2.11%

79.4th percentile

Probability of exploitation in the next 30 days. Learn more

Affected Software

Vendor	Product	Versions
Microsoft	Windows 10	1809
Microsoft	Windows 10	1909
Microsoft	Windows Server 2019	All versions

References

https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-34503Patch, Vendor Advisory
https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-34503Patch, Vendor Advisory

Timeline

Published: Jul 14, 2021
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2021-34503?

Microsoft Windows Media Foundation Remote Code Execution Vulnerability

How severe is CVE-2021-34503?

CVE-2021-34503 has a CVSS score of 7.8/10 (HIGH severity). The EPSS model estimates a 2.11% probability of exploitation in the next 30 days.

How do I fix CVE-2021-34503?

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-2021-34503?

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

Scan your code now

Source: NVD / NIST