CVE-2021-40465: Windows Text Shaping Remote Code Execution Vulnerability

Severity: medium (CVSS 6.8 v2.0)
Exploited in the wild: not listed in CISA KEV
EPSS: 2.5% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2021-10-13 · updated 2026-06-17

Description

Windows Text Shaping Remote Code Execution Vulnerability

Affected products

Microsoft Windows 10 Version 1607: 20h2, 21h1, 1607, 1809, 1909, 2004
Microsoft Windows 11 21H2: all versions
Microsoft Windows 7: sp1
Microsoft Windows 8.1: all versions
Microsoft Windows RT 8.1: all versions
Microsoft Windows Server: 20h2
Microsoft Windows Server 2008: r2-sp1, sp2
Microsoft Windows Server 2012: r2
Microsoft Windows Server 2016: 2004
Microsoft Windows Server 2019: all versions
Microsoft Windows Server 2022: all versions
Microsoft Windows 10 Version 1507: from 10.0.0 before 10.0.10240.19086 — fixed in 10.0.10240.19086
Microsoft Windows 10 1607: from 10.0.0 before 10.0.14393.4704 — fixed in 10.0.14393.4704
Microsoft Windows 10: from 10.0.0 before 10.0.17763.2237 — fixed in 10.0.17763.2237
Microsoft Windows 10 1909: from 10.0.0 before 10.0.18363.1854 — fixed in 10.0.18363.1854
Microsoft Windows 10 2004: from 10.0.0 before 10.0.19041.1288 — fixed in 10.0.19041.1288
Microsoft Windows 10 20H2: from 10.0.0 before 10.0.19042.1288 — fixed in 10.0.19042.1288
Microsoft Windows 10 21H1: from 10.0.0 before 10.0.19043.1288 — fixed in 10.0.19043.1288
Microsoft Windows 11 21H2: from 10.0.0 before 10.0.22000.258 — fixed in 10.0.22000.258
Microsoft Windows 7: from 6.1.0 before 6.1.7601.25740 — fixed in 6.1.7601.25740
Microsoft Windows 7 Service Pack 1: from 6.1.0 before 6.1.7601.25740 — fixed in 6.1.7601.25740
Microsoft Windows 8.1: from 6.3.0 before 6.3.9600.20144 — fixed in 6.3.9600.20144
Microsoft Windows Server 2008 R2 Service Pack 1: from 6.1.0 before 6.1.7601.25740 — fixed in 6.1.7601.25740
Microsoft Windows Server 2008 Service Pack 2: from 6.0.0 before 6.0.6003.21251 — fixed in 6.0.6003.21251
Microsoft Windows Server 2012: from 6.2.0 before 6.2.9200.23490 — fixed in 6.2.9200.23490
Microsoft Windows Server 2012 R2: from 6.3.0 before 6.3.9600.20144 — fixed in 6.3.9600.20144
Microsoft Windows Server 2016: from 10.0.0 before 10.0.14393.4704 — fixed in 10.0.14393.4704
Microsoft Windows Server 2019: from 10.0.0 before 10.0.17763.2237 — fixed in 10.0.17763.2237
Microsoft Windows Server 2022: from 10.0.0 before 10.0.20348.288 — fixed in 10.0.20348.288
Microsoft Windows Server version 2004: from 10.0.0 before 10.0.19041.1288 — fixed in 10.0.19041.1288

How to fix

Upgrade to a fixed version: Microsoft Windows 10 Version 1507 10.0.10240.19086; Microsoft Windows 10 1607 10.0.14393.4704; Microsoft Windows 10 10.0.17763.2237; Microsoft Windows 10 1909 10.0.18363.1854; Microsoft Windows 10 2004 10.0.19041.1288; Microsoft Windows 10 20H2 10.0.19042.1288; Microsoft Windows 10 21H1 10.0.19043.1288; Microsoft Windows 11 21H2 10.0.22000.258; Microsoft Windows 7 6.1.7601.25740; Microsoft Windows 7 Service Pack 1 6.1.7601.25740; Microsoft Windows 8.1 6.3.9600.20144; Microsoft Windows Server 2008 R2 Service Pack 1 6.1.7601.25740. Check the vendor advisory for mitigations.

References

Get alerted when CVE-2021-40465 or the next vulnerability affects your stack