Apr 2026: Windows Client Side Caching driver (csc.sys) Elevation of Privilege Vulnerability
CVE-2026-26176 Published on April 14, 2026

Windows Client Side Caching driver (csc.sys) Elevation of Privilege Vulnerability
Heap-based buffer overflow in Windows Client Side Caching driver (csc.sys) allows an authorized attacker to elevate privileges locally.

Vendor Advisory NVD

Weakness Type

Heap-based Buffer Overflow

A heap overflow condition is a buffer overflow, where the buffer that can be overwritten is allocated in the heap portion of memory, generally meaning that the buffer was allocated using a routine such as malloc().

Products Associated with CVE-2026-26176

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Microsoft Windows 10

Microsoft Windows Server 2019

Microsoft Windows Server 2022

Microsoft Windows Server 2025

Microsoft Windows 11 25h2

Microsoft Windows 11 23h2

Microsoft Windows Server 23h2

Microsoft Windows 11 24h2

Microsoft Windows Server 2016

Microsoft Windows Server 2012

Microsoft Windows Server 2012 R2

Microsoft Windows 11 26h1

Affected Versions

Microsoft Windows 10 Version 1607:

Version 10.0.14393.0 and below 10.0.14393.9060 is affected.

Microsoft Windows 10 Version 1809:

Version 10.0.17763.0 and below 10.0.17763.8644 is affected.

Microsoft Windows 10 Version 21H2:

Version 10.0.19044.0 and below 10.0.19044.7184 is affected.

Microsoft Windows 10 Version 22H2:

Version 10.0.19045.0 and below 10.0.19045.7184 is affected.

Microsoft Windows 11 version 22H3:

Version 10.0.22631.0 and below 10.0.22631.6936 is affected.

Microsoft Windows 11 Version 23H2:

Version 10.0.22631.0 and below 10.0.22631.6936 is affected.

Microsoft Windows 11 Version 24H2:

Version 10.0.26100.0 and below 10.0.26100.32690 is affected.

Microsoft Windows 11 Version 25H2:

Version 10.0.26200.0 and below 10.0.26200.8246 is affected.

Microsoft Windows 11 version 26H1:

Version 10.0.28000.0 and below 10.0.28000.1836 is affected.

Microsoft Windows Server 2012:

Version 6.2.9200.0 and below 6.2.9200.26026 is affected.

Microsoft Windows Server 2012 (Server Core installation):

Version 6.2.9200.0 and below 6.2.9200.26026 is affected.

Microsoft Windows Server 2012 R2:

Version 6.3.9600.0 and below 6.3.9600.23132 is affected.

Microsoft Windows Server 2012 R2 (Server Core installation):

Version 6.3.9600.0 and below 6.3.9600.23132 is affected.

Microsoft Windows Server 2016:

Version 10.0.14393.0 and below 10.0.14393.9060 is affected.

Microsoft Windows Server 2016 (Server Core installation):

Version 10.0.14393.0 and below 10.0.14393.9060 is affected.

Microsoft Windows Server 2019:

Version 10.0.17763.0 and below 10.0.17763.8644 is affected.

Microsoft Windows Server 2019 (Server Core installation):

Version 10.0.17763.0 and below 10.0.17763.8644 is affected.

Microsoft Windows Server 2022:

Version 10.0.20348.0 and below 10.0.20348.5020 is affected.

Microsoft Windows Server 2022, 23H2 Edition (Server Core installation):

Version 10.0.25398.0 and below 10.0.25398.2274 is affected.

Microsoft Windows Server 2025:

Version 10.0.26100.0 and below 10.0.26100.32690 is affected.

Microsoft Windows Server 2025 (Server Core installation):

Version 10.0.26100.0 and below 10.0.26100.32690 is affected.

Apr 2026: Windows Client Side Caching driver (csc.sys) Elevation of Privilege VulnerabilityCVE-2026-26176 Published on April 14, 2026

Weakness Type

Heap-based Buffer Overflow

Products Associated with CVE-2026-26176

Affected Versions

Apr 2026: Windows Client Side Caching driver (csc.sys) Elevation of Privilege Vulnerability
CVE-2026-26176 Published on April 14, 2026