VulnTideExploited vulnerabilities, by vendor. Data as of .
Known exploitedIn CISA's KEV catalog since Ransomware use: known
Microsoft Windows

CVE-2021-41379: Microsoft Windows Installer Privilege Escalation Vulnerability

Is it exploited?

Yes. CISA added it to the Known Exploited Vulnerabilities catalog on , 113 days after the CVE record was published.

How likely is exploitation in the next 30 days?
19.5%

EPSS score, percentile 97.4 of all scored records

How severe?
5.5 Medium

CVSS v3.1 base score, given by the CNA

What should I do?

CISA deadline . Apply updates per vendor instructions.

Advisories and patches (1)

Which versions are affected?

Affected

  • from 10.0.10240.0 to before 10.0.10240.19119
  • from 10.0.14393.0 to before 10.0.14393.4770
  • from 10.0.17763.0 to before 10.0.17763.2300
  • from 10.0.0 to before 10.0.17763.2300
  • from 10.0.0 to before 10.0.18363.1916
  • from 10.0.0 to before 10.0.19041.1348

and 14 more in the table below

Versions by product

Source: CISA Known Exploited Vulnerabilities (KEV) catalog, 2026.10.28, as of ; FIRST Exploit Prediction Scoring System (EPSS), v2026.06.15, as of ; CVE List V5 (CVE Program), cve_2026-10-28_0000Z, as of . About the data.

What to do

Required action, set by CISA

Apply updates per vendor instructions.

CISA due date for this action: .

Advisories and patches

Linked from CISA's catalog entry

Affected products and versions

As listed in the CVE record.

Microsoft Windows 10 Version 1507
StatusVersions
Affectedfrom 10.0.10240.0 to before 10.0.10240.19119
Microsoft Windows 10 Version 1607
StatusVersions
Affectedfrom 10.0.14393.0 to before 10.0.14393.4770
Microsoft Windows 10 Version 1809
StatusVersions
Affectedfrom 10.0.17763.0 to before 10.0.17763.2300
Microsoft Windows 10 Version 1809
StatusVersions
Affectedfrom 10.0.0 to before 10.0.17763.2300
Microsoft Windows 10 Version 1909
StatusVersions
Affectedfrom 10.0.0 to before 10.0.18363.1916
Microsoft Windows 10 Version 2004
StatusVersions
Affectedfrom 10.0.0 to before 10.0.19041.1348
Microsoft Windows 10 Version 20H2
StatusVersions
Affectedfrom 10.0.0 to before 10.0.19042.1348
Microsoft Windows 10 Version 21H1
StatusVersions
Affectedfrom 10.0.0 to before 10.0.19043.1348
Microsoft Windows 11 version 21H2
StatusVersions
Affectedfrom 10.0.22000.0 to before 10.0.22000.318
Microsoft Windows 7
StatusVersions
Affectedfrom 6.1.0 to before 6.1.7601.25769
Microsoft Windows 7 Service Pack 1
StatusVersions
Affectedfrom 6.1.0 to before 6.1.7601.25769
Microsoft Windows 8.1
StatusVersions
Affectedfrom 6.3.0 to before 6.3.9600.20174
Microsoft Windows Server 2008 R2 Service Pack 1
StatusVersions
Affectedfrom 6.1.7601.0 to before 6.1.7601.25769
Microsoft Windows Server 2008 R2 Service Pack 1 (Server Core installation)
StatusVersions
Affectedfrom 6.1.7601.0 to before 6.1.7601.25769
Microsoft Windows Server 2008 Service Pack 2
StatusVersions
Affectedfrom 6.0.6003.0 to before 6.0.6003.21282
Microsoft Windows Server 2008 Service Pack 2 (Server Core installation)
StatusVersions
Affectedfrom 6.0.6003.0 to before 6.0.6003.21282
Microsoft Windows Server 2012
StatusVersions
Affectedfrom 6.2.9200.0 to before 6.2.9200.23517
Microsoft Windows Server 2012 (Server Core installation)
StatusVersions
Affectedfrom 6.2.9200.0 to before 6.2.9200.23517
Microsoft Windows Server 2012 R2
StatusVersions
Affectedfrom 6.3.9600.0 to before 6.3.9600.20174
Microsoft Windows Server 2012 R2 (Server Core installation)
StatusVersions
Affectedfrom 6.3.9600.0 to before 6.3.9600.20174

Source: CVE List V5 (CVE Program), cve_2026-10-28_0000Z, as of . About the data.

About this vulnerability

Microsoft Windows Installer contains an unspecified vulnerability that allows for privilege escalation.

Summary: CISA's KEV catalog, as of .

  • CISA added CVE-2021-41379 to its Known Exploited Vulnerabilities (KEV) catalog on 3 Mar 2022.
  • CISA marks it as known to be used in ransomware campaigns.
  • The due date CISA sets for the required action is 17 Mar 2022.
  • The CVE record was published on 10 Nov 2021, 113 days before it was added to KEV.
  • The CVE record carries a CVSS v3.1 base score of 5.5 (Medium), given by its CNA.
  • FIRST's EPSS model puts the probability of exploitation in the next 30 days at 19.5% (percentile 97.4), as of 28 Oct 2026.
  • CISA's SSVC assessment in the CVE record: exploitation active, automatable no, technical impact total.

Source: CISA Known Exploited Vulnerabilities (KEV) catalog, 2026.10.28, as of ; CVE List V5 (CVE Program), cve_2026-10-28_0000Z, as of ; FIRST Exploit Prediction Scoring System (EPSS), v2026.06.15, as of . About the data.

Description

Windows Installer Elevation of Privilege Vulnerability

Windows Installer Elevation of Privilege Vulnerability

Source: CVE List V5 (CVE Program), cve_2026-10-28_0000Z, as of . About the data.

Weakness

  • CWE-59: Improper Link Resolution Before File Access ('Link Following')
  • CWE-1386

CWE and CAPEC are maintained by MITRE; the entries are those named in the CVE record and the KEV entry.

Timeline

DateEvent
CVE record published
Added to CISA KEV
CISA due date for the required action
CVE record last updated

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