What’s Vulnerable › Vulnerabilities

CVE-2021-34518: Microsoft Excel Remote Code Execution Vulnerability

• Severity: medium (CVSS 6.8 v2.0)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 2.4% 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 Excel 2013 Service Pack 1: 2013-sp1, 2016
• Microsoft Office Web Apps Server: 2013-sp1
• 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 Web Apps Server 2013 Service Pack 1: from 15.0.1 before 15.0.5363.1000 — fixed in 15.0.5363.1000

How to fix

Upgrade to a fixed version: Microsoft Excel 2013 Service Pack 1 15.0.5363.1000; Microsoft Excel 2016 16.0.5188.100; Microsoft Office Web Apps Server 2013 Service Pack 1 15.0.5363.1000. Check the vendor advisory for mitigations.

References

• https://msrc.microsoft.com/update-guide/vulnerability/CVE-2021-34518
• https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-34518

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