SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityModified

CVE-2021-31958

Windows NTLM Elevation of Privilege Vulnerability

HIGH 7.5EPSS 2.56%

Does this matter?

High impact if exploited, but EPSS currently rates exploitation as unlikely (2.56%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.

Description

Windows NTLM Elevation of Privilege Vulnerability

CVSS 3.1
7.5 HIGHCVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H
EPSS
2.56% probability · 85th percentile
Public exploits
None in Exploit-DB
CISA KEV
Not listed
Weakness
CWE-294
Affected
microsoft/windows 10 · microsoft/windows 7 · microsoft/windows 8.1 · microsoft/windows rt 8.1 · microsoft/windows server 2008 · microsoft/windows server 2012 · microsoft/windows server 2016 · microsoft/windows server 2019
Source
secure@microsoft.com
EPSS trend
0%3%5%26 October 2026: 2.56%26 October 202626 October 2026

EPSS 2.6% since 26 October 2026; no change recorded yet. Points are recorded when the score first appears and whenever it moves by a percentage point or more.

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