CVE-2026-70096: Windows Rich Text Edit Control Remote Code Execution Vulnerability

Severity: critical (CVSS 9.8 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 1.1% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-10-13 · updated 2026-10-31
Weakness: CWE-122

Description

Heap-based buffer overflow in Windows Rich Text Edit Control allows an unauthorized attacker to execute code over a network.

Affected products

Microsoft 365 Apps: from 16.0.1 before https://aka.ms/OfficeSecurityReleases — fixed in https://aka.ms/OfficeSecurityReleases
Microsoft Office 365 for Mac: from 1.0.0 before 16.114.26101123 — fixed in 16.114.26101123
Microsoft Office LTSC 2021: from 16.0.1 before 16.0.14334.20974 — fixed in 16.0.14334.20974
Microsoft Office LTSC for Mac 2024: from 16.0.0 before 16.114.26101123 — fixed in 16.114.26101123
Microsoft Office LTSC 2024: from 16.0.0 before 16.0.17932.21056 — fixed in 16.0.17932.21056
Microsoft Office LTSC for Mac 2021: from 16.0.1 before 16.114.26101123 — fixed in 16.114.26101123
Microsoft Windows 10 1607: from 10.0.14393.0 before 10.0.14393.9612 — fixed in 10.0.14393.9612
Microsoft Windows 10: from 10.0.17763.0 before 10.0.17763.9376 — fixed in 10.0.17763.9376
Microsoft Windows 10: from 10.0.19044.0 before 10.0.19044.7807 — fixed in 10.0.19044.7807
Microsoft Windows 10: from 10.0.19045.0 before 10.0.19045.7807 — fixed in 10.0.19045.7807
Microsoft Windows 11: from 10.0.22631.0 before 10.0.22631.7652 — fixed in 10.0.22631.7652
Microsoft Windows 11: from 10.0.26100.0 before 10.0.26100.9711 — fixed in 10.0.26100.9711
Microsoft Windows 11 25H2: from 10.0.26200.0 before 10.0.26200.9711 — fixed in 10.0.26200.9711
Microsoft Windows 11 version 26H1: from 10.0.28000.0 before 10.0.28000.3231 — fixed in 10.0.28000.3231
Microsoft Windows 11 26H2: from 10.0.26300.0 before 10.0.26300.9711 — fixed in 10.0.26300.9711
Microsoft Windows Server 2012: from 6.2.9200.0 before 6.2.9200.26434 — fixed in 6.2.9200.26434
Microsoft Windows Server 2012 R2: from 6.3.9600.0 before 6.3.9600.23470 — fixed in 6.3.9600.23470
Microsoft Windows Server 2016: from 10.0.14393.0 before 10.0.14393.9612 — fixed in 10.0.14393.9612
Microsoft Windows Server 2019: from 10.0.17763.0 before 10.0.17763.9376 — fixed in 10.0.17763.9376
Microsoft Windows Server 2022: from 10.0.20348.0 before 10.0.20348.5761 — fixed in 10.0.20348.5761
Microsoft Windows Server 2025: from 10.0.26100.0 before 10.0.26100.33650 — fixed in 10.0.26100.33650

How to fix

Upgrade to a fixed version: Microsoft 365 Apps https://aka.ms/OfficeSecurityReleases; Microsoft Office 365 for Mac 16.114.26101123; Microsoft Office LTSC 2021 16.0.14334.20974; Microsoft Office LTSC for Mac 2024 16.114.26101123; Microsoft Office LTSC 2024 16.0.17932.21056; Microsoft Office LTSC for Mac 2021 16.114.26101123; Microsoft Windows 10 1607 10.0.14393.9612; Microsoft Windows 10 10.0.17763.9376; Microsoft Windows 10 10.0.19044.7807; Microsoft Windows 10 10.0.19045.7807; Microsoft Windows 11 10.0.22631.7652; Microsoft Windows 11 10.0.26100.9711. Check the vendor advisory for mitigations.

References

https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-70096

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