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Attack ChainAIDerived

Hypothetical attack flow derived from CVE metadata – not a confirmed exploit chain

  1. Access
    Authenticate as local user
  2. Exploit
    Access Function Discovery Service
  3. Execution
    Trigger race condition in fdwsd.dll
  4. Impact
    Achieve privilege escalation to SYSTEM

Vulnerability Assessment

Weakness
CWE
OWASP Top 10:2025
A06:2025 - Insecure Design
ASVS 5.0
V15 - Secure Coding and Architecture Concurrency control, locking
MITRE ATT&CK

1 technique across 1 tactic: Privilege Escalation

The technique list with ATT&CK links and the kill-chain view is part of the Basic plan and up.

Exploitation Conditions

Authenticated local access required. Attacker must have valid user account credentials on the target Windows system. Race condition timing must be achieved during Function Discovery Service operation. Affects default installations of Windows with Function Discovery Service enabled.

Impact

Real-world risk is moderate despite the 7.0 CVSS score. The CVSS vector reveals significant exploitation barriers: local access required (AV:L), high attack complexity (AC:H) indicating precise timing manipulation needed, and low privileges required (PR:L) but still authenticated access. The AC:H rating is critical-race conditions are notoriously difficult to exploit reliably due to narrow timing windows and system-dependent behavior. No public exploit identified at time of analysis, and no CISA KEV listing confirms active exploitation. EPSS data not provided but race conditions typically have lower exploitation probability than memory corruption vulnerabilities due to reliability challenges. SSVC framework assessment: exploitation status is none (no POC), automatable is no (requires local access and precise timing), technical impact is total (full privilege escalation). Priority should be medium-patch during normal cycles for servers, prioritize only for high-value endpoints with multiple local users. This is not a critical remote or wormable threat.

Exploit ScenarioDerived

An attacker with valid domain credentials authenticates to a corporate workstation or terminal server where multiple users have local access rights. The attacker executes a custom program that repeatedly calls Function Discovery Service APIs while simultaneously manipulating shared resources (such as temporary files or registry keys) that fdwsd.dll accesses. By winning the race condition through precise timing, the attacker causes the service to perform privileged operations (like file writes or registry modifications) in a security context they control, ultimately granting them SYSTEM-level privileges to install persistent backdoors, exfiltrate credentials, or pivot to network resources.

This Week Schedule remediation this week. Why: HIGH severity (CVSS 7.0-8.9).
Patch available 0.0% exploitation probability (EPSS)

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AnalysisAIv1 – Apr 14, 2026

Privilege escalation in Windows Function Discovery Service (fdwsd.dll) allows authenticated local attackers to gain SYSTEM-level access by exploiting a race condition during shared resource handling. Affects all supported Windows 10/11 client versions and Windows Server 2012 through 2025. Vendor-released patches are available per Microsoft's May 2026 Patch Tuesday. No public exploit identified at time of analysis, but CVSS 7.0 reflects high complexity local attack requiring low privileges.

RemediationAI

Apply Microsoft's May 2026 security updates immediately through Windows Update or WSUS. Patched versions: Windows 10 1607/Server 2016 build 10.0.14393.9060, Windows 10 1809/Server 2019 build 10.0.17763.8644, Windows 10 21H2 build 10.0.19044.7184, Windows 10 22H2 build 10.0.19045.7184, Windows 11 22H3/23H2 build 10.0.22631.6936, Windows 11 24H2/Server 2025 build 10.0.26100.32690, Windows 11 25H2 build 10.0.26200.8246, Windows 11 26H1 build 10.0.28000.1836, Server 2012 build 6.2.9200.26026, Server 2012 R2 build 6.3.9600.23132, Server 2022 build 10.0.20348.5020, Server 2022 23H2 build 10.0.25398.2274. No effective workarounds exist as the Function Discovery Service is integral to Windows networking features. Prioritize patching multi-user systems and servers where authenticated local access is granted to untrusted users. Download patches from https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-32086.

Affected VersionsENISA

Windows Server 2022 10.0.20348.0 <10.0.20348.5020
Windows Server 2012 (Server Core installation) 6.2.9200.0 <6.2.9200.26026
Windows 11 Version 23H2 10.0.22631.0 <10.0.22631.6936
Windows 11 Version 25H2 10.0.26200.0 <10.0.26200.8246
Windows Server 2016 (Server Core installation) 10.0.14393.0 <10.0.14393.9060
Windows 11 version 22H3 10.0.22631.0 <10.0.22631.6936
Windows 11 Version 24H2 10.0.26100.0 <10.0.26100.32690
Windows 10 Version 1809 10.0.17763.0 <10.0.17763.8644
Windows Server 2012 6.2.9200.0 <6.2.9200.26026
Windows Server 2012 R2 (Server Core installation) 6.3.9600.0 <6.3.9600.23132
Windows Server 2016 10.0.14393.0 <10.0.14393.9060
Windows Server 2022, 23H2 Edition (Server Core installation) 10.0.25398.0 <10.0.25398.2274
Windows 11 version 26H1 10.0.28000.0 <10.0.28000.1836
Windows Server 2019 10.0.17763.0 <10.0.17763.8644
Windows 10 Version 22H2 10.0.19045.0 <10.0.19045.7184
Windows Server 2025 10.0.26100.0 <10.0.26100.32690
Windows Server 2025 (Server Core installation) 10.0.26100.0 <10.0.26100.32690
Windows 10 Version 1607 10.0.14393.0 <10.0.14393.9060
Windows Server 2012 R2 6.3.9600.0 <6.3.9600.23132
Windows Server 2019 (Server Core installation) 10.0.17763.0 <10.0.17763.8644
Windows 10 Version 21H2 10.0.19044.0 <10.0.19044.7184

Affected Packages

microsoft windows_10_version_1607_10_0_14393_9060 fix: Windows 10 Version 1607 for 32-bit Systems 10.0.14393.9060, Windows 10 Version 1607 for x64-based Systems 10.0.14393.9060
microsoft windows_10_version_1809_10_0_17763_8644 fix: Windows 10 Version 1809 for 32-bit Systems 10.0.17763.8644, Windows 10 Version 1809 for x64-based Systems 10.0.17763.8644
microsoft windows_10_version_21h2_10_0_19044_7184 fix: Windows 10 Version 21H2 for 32-bit Systems 10.0.19044.7184, Windows 10 Version 21H2 for ARM64-based Systems 10.0.19044.7184, Windows 10 Version 21H2 for x64-based Systems 10.0.19044.7184
microsoft windows_10_version_22h2_10_0_19045_7184 fix: Windows 10 Version 22H2 for 32-bit Systems 10.0.19045.7184, Windows 10 Version 22H2 for ARM64-based Systems 10.0.19045.7184, Windows 10 Version 22H2 for x64-based Systems 10.0.19045.7184
microsoft windows_11_version_23h2_10_0_22631_6936 fix: Windows 11 Version 23H2 for ARM64-based Systems 10.0.22631.6936, Windows 11 Version 23H2 for x64-based Systems 10.0.22631.6936
microsoft windows_11_version_24h2_10_0_26100_32690 fix: Windows 11 Version 24H2 for ARM64-based Systems 10.0.26100.32690, Windows 11 Version 24H2 for x64-based Systems 10.0.26100.32690
microsoft windows_11_version_25h2_10_0_26200_8246 fix: Windows 11 Version 25H2 for ARM systems 10.0.26200.8246, Windows 11 Version 25H2 for x64-based Systems 10.0.26200.8246
microsoft windows_11_version_26h1_10_0_28000_1836 fix: Windows 11 Version 26H1 for ARM64-based Systems 10.0.28000.1836, Windows 11 version 26H1 for x64-based Systems 10.0.28000.1836
microsoft windows_server_2012_6_2_9200_26026 fix: Windows Server 2012 6.2.9200.26026, Windows Server 2012 (Server Core installation) 6.2.9200.26026
microsoft windows_server_2012_r2_6_3_9600_23132 fix: Windows Server 2012 R2 6.3.9600.23132, Windows Server 2012 R2 (Server Core installation) 6.3.9600.23132
microsoft windows_server_2016_10_0_14393_9060 fix: Windows Server 2016 10.0.14393.9060, Windows Server 2016 (Server Core installation) 10.0.14393.9060
microsoft windows_server_2019_10_0_17763_8644 fix: Windows Server 2019 10.0.17763.8644, Windows Server 2019 (Server Core installation) 10.0.17763.8644
microsoft windows_server_2022_10_0_20348_5020 fix: Windows Server 2022 10.0.20348.5020, Windows Server 2022 (Server Core installation) 10.0.20348.5020
microsoft windows_server_2022_23h2_edition_10_0_25398_2274 fix: Windows Server 2022, 23H2 Edition (Server Core installation) 10.0.25398.2274
microsoft windows_server_2025_10_0_26100_32690 fix: Windows Server 2025 10.0.26100.32690, Windows Server 2025 (Server Core installation) 10.0.26100.32690
euvd windows_10_version_1607 fix: 10.0.14393.9060
euvd windows_10_version_1809 fix: 10.0.17763.8644
euvd windows_10_version_21h2 fix: 10.0.19044.7184
euvd windows_10_version_22h2 fix: 10.0.19045.7184
euvd windows_11_version_22h3 fix: 10.0.22631.6936
euvd windows_11_version_23h2 fix: 10.0.22631.6936
euvd windows_11_version_24h2 fix: 10.0.26100.32690
euvd windows_11_version_25h2 fix: 10.0.26200.8246
euvd windows_11_version_26h1 fix: 10.0.28000.1836
euvd windows_server_2012 fix: 6.2.9200.26026
euvd windows_server_2012_r2 fix: 6.3.9600.23132
euvd windows_server_2012_r2_server_core_installation fix: 6.3.9600.23132
euvd windows_server_2012_server_core_installation fix: 6.2.9200.26026
euvd windows_server_2016 fix: 10.0.14393.9060
euvd windows_server_2016_server_core_installation fix: 10.0.14393.9060
euvd windows_server_2019 fix: 10.0.17763.8644
euvd windows_server_2019_server_core_installation fix: 10.0.17763.8644
euvd windows_server_2022 fix: 10.0.20348.5020
euvd windows_server_2022_23h2_edition_server_core_installation fix: 10.0.25398.2274
euvd windows_server_2025 fix: 10.0.26100.32690
euvd windows_server_2025_server_core_installation fix: 10.0.26100.32690

Source: OSV (Open Source Vulnerabilities)

Affects your stack

Affects 36 packages in microsoft, euvd

Checking this CVE against your own stacks and servers is part of the Basic plan and up.

Technical ContextAI · show details

The Function Discovery Service (fdwsd.dll) is a Windows component responsible for discovering network resources and devices. The vulnerability stems from CWE-362 (concurrent execution using shared resource with improper synchronization). This race condition class occurs when multiple threads or processes access shared memory or file system resources without adequate locking mechanisms, creating a time-of-check-time-of-use (TOCTOU) window. An attacker with low-privilege local access can manipulate the timing of concurrent operations to cause the service (which runs with elevated privileges) to perform unintended actions, ultimately granting the attacker SYSTEM-level privileges. The fdwsd.dll component operates in the context of a Windows service, making successful exploitation particularly impactful as it bridges the gap between standard user and administrative control.

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  • Exploit and PoC references, threat intelligence from 22 sources

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Severity by source

Vendor (microsoft) PRIMARY 7.0 HIGH
AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H
ENISA EUVD HIGH
CIRCL (temporal) 6.1 MEDIUM

Primary rating from Vendor (microsoft).

CVSS VectorVendor: microsoft

Attack Vector
Local
Attack Complexity
High
Privileges Required
Low
User Interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

Lifecycle Timeline

2
Patch released
Apr 14, 2026 - 17:46 nvd
Patch available
CVE Published
Apr 14, 2026 - 16:58 nvd
HIGH 7.0

DescriptionCVE.org

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

Executive ViewAI

Why It Matters

CVE-2026-32086 is a privilege escalation vulnerability in Windows Function Discovery Service affecting all supported Windows 10, 11, and Server versions that allows authenticated local users to gain SYSTEM-level access. Organizations must prioritize patching immediately, as this impacts domain-joined and standalone systems across client and server infrastructure where any authenticated user can trigger the flaw.

Business Impact: High
Compensating Controls

Apply vendor patch. Interim mitigations pending patch deployment: restrict local system access through Group Policy (disable non-essential local user account creation), implement application whitelisting to limit fdwsd.dll interactions, monitor Windows Event Viewer for privilege escalation attempts (Event ID 4688 with process elevation patterns), and segment administrative access to enforce privilege separation on critical systems.

Threat Intelligence Overview

EPSS Score
0.0%
Top 89% exploitable
Threat Intel
1
1 source
Vendor Action
See Below
Required. The vulnerability documented by this CVE requires customer action to resolve.
Vendor Status
Publicly Disclosed:No
Exploited:No
Latest Software Release:Exploitation Less Likely
Data Quality
7 sources
Confidence: High

How this decision was reached

The engine reads each signal below and applies a fixed list of rules from top to bottom. The first rule that matches sets the recommended action – like a statement, every line is shown.

SignalValue
Severity HIGH
CISA KEV No
Public POC No
EPSS 0.0%
Patch available Yes
Active threat No
Deciding rule
HIGH severity (CVSS 7.0-8.9)
What every action level means
Emergency Immediate action required. Criteria: CRITICAL + in CISA KEV (actively exploited) without patch, OR CRITICAL + EPSS > 30% without patch, OR CRITICAL + active threat signals without patch.
Act Now Prioritize within 24-48h. Criteria: in KEV with patch available, OR CRITICAL + public POC, OR HIGH + EPSS > 10%, OR CRITICAL + active threat, OR any CRITICAL severity.
This Week Schedule remediation this week. Criteria: HIGH severity (CVSS 7.0-8.9). Patch within normal change window.
This Month Plan within 30 days. Criteria: MEDIUM severity (CVSS 4.0-6.9), lower exploitation probability. Include in regular patch cycle.
Monitor Track and reassess. Criteria: LOW severity (CVSS 0.1-3.9), minimal exploitation risk. No immediate action needed.

SSVC AssessmentENISA

SSVC Decision
Scheduled
Exploitation
None
System Exposure· derived
Small
Automatable
No
Human Impact
High
Technical Impact
Total

Priority Score

40
Low Medium High Critical
KEV: 0
EPSS: 0
CVSS: +35
PoC: 0
Weaponized: 0
Threat intel: 0
Gov advisory: +5

Attack Technique

Information disclosure occurs when an application unintentionally exposes sensitive data that aids attackers in reconnaissance or directly compromises security.

Race conditions occur when multiple concurrent requests exploit the brief time gap between checking a condition and acting upon it (TOCTOU - Time of Check, Time of Use).

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