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Attack ChainAIDerived

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

  1. Access
    Obtain authenticated local user session
  2. Delivery
    Identify race condition window in Audio Service memory allocation
  3. Exploit
    Race concurrent API calls to trigger use-after-free
  4. Execution
    Reclaim freed heap region with attacker-controlled content
  5. Persist
    Redirect execution within AudioSrv privileged context
  6. Impact
    Achieve NT AUTHORITY\SYSTEM privilege escalation

Vulnerability Assessment

Weakness
CWE
ASVS 5.0
V15 - Secure Coding and Architecture Memory lifecycle management
MITRE ATT&CK

2 techniques across 2 tactics: Execution, Privilege Escalation

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

Exploitation Conditions

Exploitation requires an authenticated local user account (PR:L); the attack vector is strictly local (AV:L), making remote unauthenticated exploitation impossible. The high attack complexity (AC:H) reflects a race condition: the attacker must win a timing-dependent window between object deallocation and reuse in the Audio Service's multi-threaded execution, requiring repeated attempts or careful synchronization primitives. Windows Audio Service (AudioSrv) must be running - it is enabled and started by default on all Windows desktop editions but may be disabled on hardened Windows Server deployments that have no audio requirement, in which case the attack surface is absent. No special configuration or non-default feature is required on standard workstation builds. Limiting factors include: the local-only attack vector restricting exploitation to already-present users, and the AC:H race condition reducing reliability and preventing trivially automatable mass exploitation.

Impact

The CVSS 7.0 score with AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H accurately reflects this as a local privilege escalation with meaningful exploitation difficulty - the AC:H metric captures the race-condition requirement, which substantially reduces automated and opportunistic exploitability. EPSS data was not supplied; however, Windows LPE vulnerabilities in core system services are historically attractive as post-exploitation primitives for ransomware operators and nation-state actors who already hold an initial foothold. No public exploit code has been observed and CISA has not added this to the Known Exploited Vulnerabilities catalog, suggesting exploitation remains private or theoretical at this stage. The S:U (scope unchanged) and PR:L metrics bound the attacker to an already-authenticated, already-present user on the system, meaning this flaw is a second-stage capability rather than an initial access vector. Defenders should prioritize patch deployment on workstations and endpoints with untrusted or shared user access, as those are the environments where low-privileged attackers are most likely to already exist.

Exploit ScenarioDerived

An attacker with a standard local user account - obtained via phishing, credential theft, or lateral movement - identifies the race condition window in Windows Audio Service's memory allocation path. By racing concurrent API calls against the Audio Service to trigger the use-after-free condition, the attacker controls the freed memory region to redirect code execution within the privileged service context, yielding SYSTEM-level access. No public proof-of-concept exists, but the race condition requirement means the attacker may need to run the attempt repeatedly to succeed, which may generate detectable anomalous Audio Service API activity.

This Week Schedule remediation this week. Why: HIGH severity (CVSS 7.0-8.9).
Patch available 0.3% exploitation probability (EPSS)

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AnalysisAIv1 – Sep 09, 2026

Local privilege escalation in Windows Audio Service (AudioSrv) exploits a use-after-free condition (CWE-416) to allow an authenticated local attacker to gain SYSTEM-level privileges on unpatched Windows 10, Windows 11, and Windows Server 2019-2025 systems. The attack requires low user privileges and high complexity to execute, consistent with a race condition in the service's memory management. Microsoft has released patches across all affected Windows versions; no public exploit code or CISA KEV listing has been identified at time of analysis.

RemediationAI

Apply the Microsoft security update delivering the fixed Audio Service builds for each platform: Windows 10 1809 and Server 2019 to build 10.0.17763.9245 or later; Windows 10 21H2 to 10.0.19044.7725 or later; Windows 10 22H2 to 10.0.19045.7725 or later; Windows 11 23H2 to 10.0.22631.7582 or later; Windows 11 24H2 and Server 2025 to 10.0.26100.9445 or later; Windows 11 25H2 to 10.0.26200.9445 or later; Windows 11 26H1 to 10.0.28000.2954 or later; Windows Server 2022 to 10.0.20348.5622 or later; Windows Server 2025 Server Core to 10.0.26100.33438 or later. Updates are available via Windows Update, Microsoft Update Catalog, and WSUS. The MSRC advisory is at https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-69540. Where immediate patching is not feasible on server systems that do not require audio functionality, disabling the Windows Audio Service (AudioSrv) and Windows Audio Endpoint Builder (AudioEndpointBuilder) services eliminates the attack surface entirely; note this will prevent all audio output and may affect notification audio and communication applications - evaluate impact before applying in production.

Affected VersionsENISA

Windows 10 Version 21H2 10.0.19044.0 <10.0.19044.7725
Windows 11 version 26H1 10.0.28000.0 <10.0.28000.2954
Windows Server 2025 10.0.26100.0 <10.0.26100.33438
Windows 11 Version 25H2 10.0.26200.0 <10.0.26200.9445
Windows 10 Version 1809 10.0.17763.0 <10.0.17763.9245
Windows 11 Version 24H2 10.0.26100.0 <10.0.26100.9445
Windows Server 2019 10.0.17763.0 <10.0.17763.9245
Windows Server 2025 (Server Core installation) 10.0.26100.0 <10.0.26100.33438
Windows Server 2022 10.0.20348.0 <10.0.20348.5622
Windows 11 Version 23H2 10.0.22631.0 <10.0.22631.7582
Windows 10 Version 22H2 10.0.19045.0 <10.0.19045.7725
Windows Server 2019 (Server Core installation) 10.0.17763.0 <10.0.17763.9245

Affected Packages

euvd windows_10_version_1809 fix: 10.0.17763.9245
euvd windows_10_version_21h2 fix: 10.0.19044.7725
euvd windows_10_version_22h2 fix: 10.0.19045.7725
euvd windows_11_version_23h2 fix: 10.0.22631.7582
euvd windows_11_version_24h2 fix: 10.0.26100.9445
euvd windows_11_version_25h2 fix: 10.0.26200.9445
euvd windows_11_version_26h1 fix: 10.0.28000.2954
euvd windows_server_2019 fix: 10.0.17763.9245
euvd windows_server_2019_server_core_installation fix: 10.0.17763.9245
euvd windows_server_2022 fix: 10.0.20348.5622
euvd windows_server_2025 fix: 10.0.26100.33438
euvd windows_server_2025_server_core_installation fix: 10.0.26100.33438

Source: OSV (Open Source Vulnerabilities)

Affects your stack

Affects 12 packages in euvd

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

Technical ContextAI · show details

Windows Audio Service (AudioSrv/AudioEndpointBuilder) is a privileged system service that manages audio device routing, session management, and inter-process audio communication; it runs as LocalSystem on most Windows editions. CWE-416 (Use After Free) occurs when a heap-allocated object is freed while a dangling reference remains accessible - in a concurrent, multi-threaded service like Audio Service, a race condition between deallocation and re-access creates an exploitable window. An attacker can manipulate the freed memory region (e.g., by racing object reallocation) to redirect control flow or corrupt privileged data structures, elevating from a standard user to NT AUTHORITY\SYSTEM. The AC:H CVSS metric directly reflects the race-condition dependency. Affected builds span Windows 10 (1809, 21H2, 22H2), Windows 11 (23H2, 24H2, 25H2, 26H1), Windows Server 2019, 2022, and 2025, indicating the vulnerable code path is shared across a broad Windows codebase generation.

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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
vuln.today AI 7.0 HIGH

Local-only race condition requiring low-privileged user; full C/I/A impact upon successful SYSTEM-level escalation; scope unchanged.

3.1 AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H
4.0 AV:L/AC:H/AT:P/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N

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 available
Sep 08, 2026 - 18:35 EUVD
CVE Published
Sep 08, 2026 - 18:19 nvd
HIGH 7.0

DescriptionCVE.org

Use after free in Windows Audio Service allows an authorized attacker to elevate privileges locally.

Executive ViewAI

Why It Matters

Windows Audio Service contains a local privilege escalation vulnerability (CWE-416) affecting Windows 10, 11, and Server 2019-2025. Any authenticated local user can exploit a race condition to gain SYSTEM-level access, enabling complete system compromise and lateral movement within the organization. This directly threatens systems in your Windows infrastructure, particularly multi-user environments and systems handling sensitive workloads.

Business Impact: High
Compensating Controls

Apply vendor patch.

Threat Intelligence Overview

EPSS Score
0.3%
Top 83% exploitable
Prevalence
Ubiquitous
Windows deployed across virtually all enterprise and consumer environments
Vendor Status
Publicly Disclosed:No
Exploited:No
Latest Software Release:Exploitation Less Likely
Data Quality
5 sources
Confidence: Medium

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 0.3%
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
Defer
Exploitation
None
System Exposure· derived
Small
Automatable
No
Human Impact
High
Technical Impact
Total

Priority Score

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

Attack Technique

Use-after-free vulnerabilities occur when a program continues to access memory through a pointer after that memory has been deallocated.

Memory corruption occurs when a program writes data beyond the boundaries of allocated memory regions or accesses memory in unintended ways, violating the integrity of the process's address space.

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