CVE-2026-20839

Improper access control in Windows Client-Side Caching (CSC) Service allows an authorized attacker to disclose information locally.

CVSS v3 5.5 MEDIUM

5.5^/10

CVSS v3 : MEDIUM

Vector :

Exploitability : 1.8 / Impact : 3.6

Attack Vector LOCAL

Attack Complexity LOW

Privileges Required LOW

User Interaction NONE

Confidentiality Impact HIGH

Integrity Impact NONE

Availability Impact NONE

Scope UNCHANGED

References

Link	Resource
https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-20839	Vendor Advisory

Configurations

Configuration 1 (hide)

OR	cpe:2.3:o:microsoft:windows_10_1607:::::::x64:*
	cpe:2.3:o:microsoft:windows_10_1607:::::::x86:*
	cpe:2.3:o:microsoft:windows_10_1809:::::::x64:*
	cpe:2.3:o:microsoft:windows_10_1809:::::::x86:*
	cpe:2.3:o:microsoft:windows_10_21h2::::::::
	cpe:2.3:o:microsoft:windows_10_22h2::::::::
	cpe:2.3:o:microsoft:windows_11_23h2::::::::
	cpe:2.3:o:microsoft:windows_11_24h2::::::::
	cpe:2.3:o:microsoft:windows_11_25h2::::::::
	cpe:2.3:o:microsoft:windows_server_2008:r2:sp1:::::x64:*
	cpe:2.3:o:microsoft:windows_server_2012:-:::::::*
	cpe:2.3:o:microsoft:windows_server_2012:r2:::::::*
	cpe:2.3:o:microsoft:windows_server_2016::::::::
	cpe:2.3:o:microsoft:windows_server_2019::::::::
	cpe:2.3:o:microsoft:windows_server_2022::::::::
	cpe:2.3:o:microsoft:windows_server_2022_23h2::::::::
	cpe:2.3:o:microsoft:windows_server_2025::::::::

History

No history.

Information

Published : 2026-01-13 18:16

Updated : 2026-01-15 14:30

NVD link : CVE-2026-20839

Mitre link : CVE-2026-20839

CVE.ORG link : CVE-2026-20839

JSON object : View

Products Affected

microsoft

windows_10_1809
windows_server_2022_23h2
windows_server_2016
windows_server_2022
windows_server_2008
windows_11_24h2
windows_10_1607
windows_server_2025
windows_server_2019
windows_10_21h2
windows_10_22h2
windows_11_25h2
windows_11_23h2
windows_server_2012

CWE

CWE-284

Improper Access Control

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