How severe is CVE-2021-27059?

CVE-2021-27059 has a CVSS 3.1 base score of 7.6 (HIGH). EPSS estimates a 6.1% probability of exploitation in the next 30 days. It is listed in the CISA Known Exploited Vulnerabilities catalog.

CVE-2021-27059: Microsoft Office Remote Code Execution Vulnerability

CISA Known Exploited Vulnerabilities

Microsoft Office Remote Code Execution Vulnerability is confirmed as actively exploited and is listed in the CISA KEV catalog.

Added to KEV

2021-11-03

Remediation due

2021-11-17

Required action
Apply updates per vendor instructions.

CISA notes
https://nvd.nist.gov/vuln/detail/CVE-2021-27059

Description

Microsoft Office Remote Code Execution Vulnerability

Severity

CVSS 3.1 · CNA7.6 HIGH

CVSS:3.1/AV:N/AC:H/PR:H/UI:R/S:C/C:H/I:H/A:H/E:U/RL:O/RC:C

SSVC · CISA-ADP

Exploitationactive

Automatableno

Technical impacttotal

Exploitation Context

as of October 12, 2026

All KEV statistics→

CISA added CVE-2021-27059 to the KEV catalog 237 days after its CVE record was published.
It is one of 390 Microsoft entries in the CISA KEV catalog, and one of 83 added in 2021.
Its current EPSS score (6.1%) is higher than that of 20% of CISA KEV entries.

Affected Products

Vendor	Product	Affected versions
Microsoft	Microsoft Microsoft Office 2010 Service Pack 2	13.0.0.0 to <14.0.7266.5000
Microsoft	Microsoft Microsoft Office 2013 Service Pack 1	15.0.0 to <publication
Microsoft	Microsoft Microsoft Office 2016	16.0.0 to <16.0.5134.1000

References

2 Links

Vendor advisories

Microsoft Office Remote Code Execution Vulnerability

Other references

https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-27059

Record Details

Published

2021-03-11

Last updated

2026-08-19

Assigner (CNA)

microsoft

Credited to

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CVE record data © The MITRE Corporation, used under the CVE Terms of Use. Exploited-in-the-wild data from the CISA Known Exploited Vulnerabilities catalog (CC0). Exploit prediction scores by FIRST EPSS (first.org/epss). This site is not endorsed or certified by MITRE, NVD, CISA, or FIRST.