CVE-2026-77894: Windows Installer Elevation of Privilege Vulnerability
Concurrent execution using shared resource with improper synchronization ('race condition') in Windows Installer allows an authorized attacker to elevate privileges locally.
Other sources
Windows Installer Elevation of Privilege Vulnerability
— Microsoft
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
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Fixed in 6.3.9600.23397Patch KB5123066 - Upgrade
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Fixed in 6.2.9200.26349Patch KB5123065 - Upgrade
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Fixed in 10.0.14393.9512Patch KB5123099 - Upgrade
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Fixed in 10.0.28000.2954Patch KB5124012 - Upgrade
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Fixed in 10.0.20348.5622Patch KB5122882 - Upgrade
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Fixed in 10.0.26100.9445Patch KB5124008 - Upgrade
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Fixed in 10.0.26100.33438Patch KB5122871 - Upgrade
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Fixed in 10.0.22631.7582Patch KB5122880 - Upgrade
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Fixed in 10.0.17763.9245Patch KB5122876 - Upgrade
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Fixed in 10.0.26200.9445Patch KB5124008 - Upgrade
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Fixed in 10.0.19045.7725Patch KB5122878 - Upgrade
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Fixed in 10.0.19044.7725Patch KB5122878
Event History
Frequently Asked Questions
Who can exploit this vulnerability?
An attacker must already be authorized to access the affected system and must exploit the issue locally. The provided data does not indicate that remote exploitation is possible.
Which systems are listed as affected?
The affected software list includes Microsoft Windows 10, Windows 11, Windows Server 2012, Windows Server 2012 R2, Windows Server 2016, Windows Server 2019, Windows Server 2022, and Windows Server 2025.
What level of impact could successful exploitation have?
Successful exploitation can elevate local privileges. The severity vector indicates high impacts to confidentiality, integrity, and availability.