CVE-2026-83798: Windows Update Stack Spoofing Vulnerability
Improper verification of cryptographic signature in Windows Update Stack allows an authorized attacker to perform spoofing locally.
Other sources
Windows Update Stack Spoofing Vulnerability
— Microsoft
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade to a fixed release to a version that resolves this vulnerability.
Fixed in 6.2.9200.26434Patch KB5126835 - Upgrade
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Fixed in 6.3.9600.23470Patch KB5126836 - Upgrade
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Fixed in 10.0.26300.9711Patch KB5127648 - Upgrade
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Fixed in 10.0.22631.7652Patch KB5126653 - Upgrade
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Fixed in 10.0.14393.9612Patch KB5126868 - Upgrade
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Fixed in 10.0.28000.3231Patch KB5127646 - Upgrade
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Fixed in 10.0.26100.33650Patch KB5126646 - Upgrade
Upgrade to a fixed release to a version that resolves this vulnerability.
Fixed in 10.0.26100.9711Patch KB5127648 - Upgrade
Upgrade to a fixed release to a version that resolves this vulnerability.
Fixed in 10.0.26200.9711Patch KB5127648 - Upgrade
Upgrade to a fixed release to a version that resolves this vulnerability.
Fixed in 10.0.19044.7807Patch KB5126657 - Upgrade
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Fixed in 10.0.17763.9376Patch KB5126651 - Upgrade
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Fixed in 10.0.20348.5761Patch KB5126655
Event History
Frequently Asked Questions
Who can exploit this vulnerability?
An attacker must already be authorized on the affected system and must be able to act locally. The provided information does not indicate that remote or unauthenticated exploitation is possible.
Which systems should be assessed?
Assess Microsoft Windows 10, Windows 11, and Windows Server 2012, 2012 R2, 2016, 2019, 2022, and 2025 systems. The data does not identify specific affected build numbers or update levels.
What is the likely security impact?
Successful exploitation allows local spoofing through improper cryptographic-signature verification in the Windows Update Stack. The supplied severity vector indicates an integrity impact, with no stated confidentiality or availability impact.