Use-After-Free in Windows Clipboard Server Enables Local Privilege Escalation

Publication date: 2026-01-13

Last updated on: 2026-01-13

Assigner: Microsoft Corporation

Description

Use after free in Windows Clipboard Server allows an unauthorized attacker to elevate privileges locally.

CVSS Scores

EPSS Scores

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Meta Information

Published

2026-01-13

Last Modified

2026-01-13

Generated

2026-07-06

AI Q&A

2026-01-14

EPSS Evaluated

2026-07-05

NVD

CVE-2026-20844

Affected Vendors & Products

Vendor	Product	Version / Range
microsoft	windows_clipboard_server	*

Helpful Resources

Exploitability

CWE

KEV

CWE ID	Description
CWE-362	The product contains a concurrent code sequence that requires temporary, exclusive access to a shared resource, but a timing window exists in which the shared resource can be modified by another code sequence operating concurrently.
CWE-416	The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory "belongs" to the code that operates on the new pointer.

Attack-Flow Graph

Executive Summary

This vulnerability is a use-after-free issue in the Windows Clipboard Server that allows an unauthorized attacker to elevate their privileges locally on the affected system. [1]

Impact Analysis

An attacker exploiting this vulnerability can gain elevated privileges on the local system, potentially allowing them to perform actions that require higher permissions, which can compromise system security and integrity. [1]

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