SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityAnalyzed

CVE-2021-27059

Microsoft Office Remote Code Execution Vulnerability

KEVHIGH 7.6EPSS 6.08%

Does this matter?

Known to be exploited in the wild (CISA KEV, CISA remediation deadline 17 November 2021). Treat as an emergency change: patch or isolate now, then hunt for prior compromise.

Description

Microsoft Office Remote Code Execution Vulnerability

CVSS 3.1
7.6 HIGHCVSS:3.1/AV:N/AC:H/PR:H/UI:R/S:C/C:H/I:H/A:H
EPSS
6.08% probability · 93th percentile
Public exploits
None in Exploit-DB
CISA KEV
Listed 3 November 2021 · due 17 November 2021
Affected
microsoft/office · microsoft/office 2016
Source
secure@microsoft.com
EPSS trend
0%5%10%26 October 2026: 6.08%26 October 202626 October 2026

EPSS 6.1% since 26 October 2026; no change recorded yet. The dashed line is the ten per cent mark our analysts treat as “patch before the next change window”. Points are recorded when the score first appears and whenever it moves by a percentage point or more.

CISA notes

Apply updates per vendor instructions. https://nvd.nist.gov/vuln/detail/CVE-2021-27059

Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.