CVE-2026-42836

Analyzed Analyzed - Analysis Complete

Race Condition in Function Discovery Service

Publication date: 2026-06-09

Last updated on: 2026-06-11

Assigner: Microsoft Corporation

Description

Concurrent execution using shared resource with improper synchronization ('race condition') in Function Discovery Service (fdwsd.dll) allows an authorized attacker to elevate privileges locally.

CVSS Scores

EPSS Scores

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Meta Information

Published

2026-06-09

Last Modified

2026-06-11

Generated

2026-06-30

AI Q&A

2026-06-10

EPSS Evaluated

2026-06-28

NVD

CVE-2026-42836

EUVD

EUVD-2026-35590

Affected Vendors & Products

Vendor	Product	Version / Range
microsoft	windows_server_2012	r2
microsoft	windows_server_2012	*
microsoft	windows_10_1607	to 10.0.14393.9234 (exc)
microsoft	windows_10_1607	to 10.0.14393.9234 (exc)
microsoft	windows_10_1809	to 10.0.17763.8880 (exc)
microsoft	windows_10_1809	to 10.0.17763.8880 (exc)
microsoft	windows_10_21h2	to 10.0.19044.7417 (exc)
microsoft	windows_10_21h2	to 10.0.19044.7417 (exc)
microsoft	windows_10_21h2	to 10.0.19044.7417 (exc)
microsoft	windows_10_22h2	to 10.0.19045.7417 (exc)
microsoft	windows_10_22h2	to 10.0.19045.7417 (exc)
microsoft	windows_10_22h2	to 10.0.19045.7417 (exc)
microsoft	windows_11_23h2	to 10.0.22631.7219 (exc)
microsoft	windows_11_23h2	to 10.0.22631.7219 (exc)
microsoft	windows_11_24h2	to 10.0.26100.8655 (exc)
microsoft	windows_11_24h2	to 10.0.26100.8655 (exc)
microsoft	windows_11_25h2	to 10.0.26200.8655 (exc)
microsoft	windows_11_25h2	to 10.0.26200.8655 (exc)
microsoft	windows_11_26h1	to 10.0.28000.2269 (exc)
microsoft	windows_11_26h1	to 10.0.28000.2269 (exc)
microsoft	windows_server_2016	to 10.0.14393.9234 (exc)
microsoft	windows_server_2019	to 10.0.17763.8880 (exc)
microsoft	windows_server_2022	to 10.0.20348.5256 (exc)
microsoft	windows_server_2025	to 10.0.26100.32995 (exc)

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

Compliance Impact

This vulnerability allows an authorized attacker to elevate privileges locally through a race condition in the Function Discovery Service. Such unauthorized privilege escalation can lead to unauthorized access or modification of sensitive data, which may impact compliance with standards and regulations like GDPR and HIPAA that require strict access controls and protection of sensitive information.

However, no specific information about compliance impact or regulatory considerations is provided in the available resources.

Executive Summary

This vulnerability is a race condition in the Function Discovery Service (fdwsd.dll) caused by concurrent execution using a shared resource without proper synchronization.

It allows an authorized attacker to elevate their privileges locally on the affected system.

Impact Analysis

The vulnerability can allow an authorized attacker to elevate their privileges on the local system.

This means the attacker could gain higher-level permissions than intended, potentially leading to unauthorized access to sensitive data or system functions.

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