What’s Vulnerable › Vulnerabilities

CVE-2021-34501: Microsoft Excel Remote Code Execution Vulnerability

• Severity: medium (CVSS 6.8 v2.0)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 51.7% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2021-07-14 · updated 2026-08-10

Description

Microsoft Excel Remote Code Execution Vulnerability

Affected products

• Microsoft 365 Apps: all versions
• Microsoft Excel 2013 Service Pack 1: 2013-sp1, 2016
• Microsoft Office: 2019
• Microsoft Office Online Server: all versions
• Microsoft 365 Apps: from 16.0.1 before https://aka.ms/OfficeSecurityReleases — fixed in https://aka.ms/OfficeSecurityReleases
• Microsoft Excel 2013 Service Pack 1: from 15.0.0.0 before 15.0.5363.1000 — fixed in 15.0.5363.1000
• Microsoft Excel 2016: from 16.0.0.0 before 16.0.5188.100 — fixed in 16.0.5188.100
• Microsoft Office 2019 for Mac: from 16.0.0 before 16.51.210711.01 — fixed in 16.51.210711.01
• Microsoft Office: from 19.0.0 before https://aka.ms/OfficeSecurityReleases — fixed in https://aka.ms/OfficeSecurityReleases
• Microsoft Office Online Server: from 16.0.1 before 16.0.10376.20001 — fixed in 16.0.10376.20001

How to fix

Upgrade to a fixed version: Microsoft 365 Apps https://aka.ms/OfficeSecurityReleases; Microsoft Excel 2013 Service Pack 1 15.0.5363.1000; Microsoft Excel 2016 16.0.5188.100; Microsoft Office 2019 for Mac 16.51.210711.01; Microsoft Office https://aka.ms/OfficeSecurityReleases; Microsoft Office Online Server 16.0.10376.20001. Check the vendor advisory for mitigations.

References

• https://msrc.microsoft.com/update-guide/vulnerability/CVE-2021-34501
• https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-34501
• https://www.zerodayinitiative.com/advisories/ZDI-21-969/

Get alerted when CVE-2021-34501 or the next vulnerability affects your stack