CVE-2021-34518High· 7.8▾ Twilight

Microsoft Excel Remote Code Execution Vulnerability

▾ Twilight zone — High severity, or a signal on a lesser flaw

Depth score43/ 100 · Moderate

impact 42.9 · likelihood 0.5 · exploitation 0

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Proof of concept

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Published

Jul 14, 2021

Updated

Aug 10, 2026

CVSS

7.8

Vendor

microsoft

Product

excel

CWE

—

Depth score

43 · Moderate

EPSS

2.4% · p84

Platforms

—

Source

NVD

Vector

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

EPSS history

Exploit-prediction probability, daily snapshots since Aug 10.

2.2% → 2.4%▲ 0.2%

Timeline

Disclosure to exploitation, from the record and what we observed since indexing it.

4 events · 1910 days

Jul 14, 2021Published
Disclosed via NVD
Aug 10, 2026Record revised
Last analysed / modified upstream
Aug 10, 2026EPSS first tracked
2.2%
Oct 6, 2026EPSS peak
2.2% → 2.4%

microsoft #nvd

Affected

excel = 2013
excel = 2016
office_web_apps_server = 2013

Full technical detail▾

Overview

Microsoft Excel Remote Code Execution Vulnerability

Affected

excel = 2013
excel = 2016
office_web_apps_server = 2013

Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.

References

Related vulnerabilities

Connected by shared product, vendor, weakness, or advisory.

#nvd