Processor optimization removal or modification of security-critical code in Microsoft Windows and Windows Server - CVE-2026-84004

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Main Vulnerability Database Vulnerabilities #VU165538

Processor optimization removal or modification of security-critical code in Microsoft Windows and Windows Server - CVE-2026-84004

Published: November 11, 2026


Vulnerability identifier: #VU165538
CSH Severity: Low
CVSS v4: 6.8 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-84004
CWE-ID: CWE-1037
Exploitation vector: Local access
Exploit availability: No public exploit available

Vulnerability details

The vulnerability allows a local user to disclose sensitive information processed by an affected AMD Zen processor.

The vulnerability exists due to processor optimization removal or modification of security-critical code in AMD Zen processors when executing security-critical code. A local user can exploit these optimizations while running in another security context to infer data transiently processed by the affected processor.


Affected software

Microsoft Windows
Windows Server

How to mitigate CVE-2026-84004

Install security update from vendor's website.

Microsoft Windows - addressed in versions 10 21H2 10.0.19044.7807, 10 22H2 10.0.19045.7807, 10 1607 10.0.14393.9612, 10 1809 10.0.17763.9376, 11 23H2 10.0.22631.7652, 11 24H2 10.0.26100.9711, 11 25H2 10.0.26200.9711, 11 26H1 10.0.28000.3231
Windows Server - addressed in versions 2012 R2 6.3.9600.23470, 2012 6.2.9200.26434, 2016 10.0.14393.9612, 2019 10.0.17763.9376, 2022 10.0.20348.5761, 2025 10.0.26100.33650

External References

Related Security Bulletins