CVE-2026-96950

Analyzed Analyzed - Analysis Complete

Use After Free in Windows UDFs Driver Enables Local Privilege Escalation

Publication date: 2026-10-13

Last updated on: 2026-10-16

Assigner: Microsoft Corporation

Description

Use after free in Windows Universal Disk Format File System Driver (UDFS) allows an authorized attacker to elevate privileges locally.

CVSS Scores

EPSS Scores

Probability:
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Meta Information

Published

2026-10-13

Last Modified

2026-10-16

Generated

2026-10-19

AI Q&A

2026-10-14

EPSS Evaluated

2026-10-18

NVD

CVE-2026-96950

EUVD

EUVD-2026-100273

Affected Vendors & Products

Vendor	Product	Version / Range
microsoft	windows_server_2012	r2
microsoft	windows_server_2012	*
microsoft	windows_server_2022	to 10.0.20348.5761 (exc)
microsoft	windows_10_1607	to 10.0.14393.9612 (exc)
microsoft	windows_10_1607	to 10.0.14393.9612 (exc)
microsoft	windows_10_1809	to 10.0.17763.9376 (exc)
microsoft	windows_10_1809	to 10.0.17763.9376 (exc)
microsoft	windows_10_21h2	to 10.0.19044.7807 (exc)
microsoft	windows_10_21h2	to 10.0.19044.7807 (exc)
microsoft	windows_10_21h2	to 10.0.19044.7807 (exc)
microsoft	windows_11_23h2	to 10.0.22631.7652 (exc)
microsoft	windows_11_23h2	to 10.0.22631.7652 (exc)
microsoft	windows_11_24h2	to 10.0.26100.9711 (exc)
microsoft	windows_11_24h2	to 10.0.26100.9711 (exc)
microsoft	windows_11_25h2	to 10.0.26200.9711 (exc)
microsoft	windows_11_25h2	to 10.0.26200.9711 (exc)
microsoft	windows_11_26h1	to 10.0.28000.3231 (exc)
microsoft	windows_11_26h1	to 10.0.28000.3231 (exc)
microsoft	windows_11_26h2	to 10.0.26300.9711 (exc)
microsoft	windows_11_26h2	to 10.0.26300.9711 (exc)
microsoft	windows_server_2016	to 10.0.14393.9612 (exc)
microsoft	windows_server_2019	to 10.0.17763.9376 (exc)
microsoft	windows_server_2025	to 10.0.26100.33650 (exc)
microsoft	windows_10_22h2	to 10.0.19045.7807 (exc)
microsoft	windows_10_22h2	to 10.0.19045.7807 (exc)
microsoft	windows_10_22h2	to 10.0.19045.7807 (exc)

Helpful Resources

Exploitability

CWE

KEV

CWE ID	Description
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 Any operations using the original pointer are no longer valid because the memory "belongs" to the code that operates on the new pointer.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 is a use-after-free vulnerability in the Windows Universal Disk Format File System Driver (UDFS). It allows an authorized attacker with local access to exploit memory corruption and elevate their privileges on the system.

Detection Guidance

Detection typically requires monitoring for unusual system behavior or crashes related to the UDFS driver. Check Windows Event Viewer for application or system crashes involving udfs.sys. Use commands like 'sfc /scannow' to verify system file integrity and 'driverquery' to list loaded drivers for suspicious entries.

Impact Analysis

An attacker could gain higher-level permissions on your system, potentially allowing them to install programs, view or delete data, or create new accounts with full user rights.

Compliance Impact

This vulnerability allows local privilege escalation through a use-after-free flaw in the Windows UDFS driver. Such flaws could potentially enable unauthorized access to sensitive data or system functions, which may impact compliance with standards like GDPR (data protection) or HIPAA (healthcare data privacy) by increasing the risk of data breaches or unauthorized system access.

Mitigation Strategies

Apply the latest Windows security updates from Microsoft Update immediately. Disable the UDFS driver if not required by unregistering it via 'sc stop udfs' and 'sc config udfs start= disabled'. Monitor Microsoft's advisory for patches and restrict local user privileges.

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