Attack ChainAIDerived
Hypothetical attack flow derived from CVE metadata – not a confirmed exploit chain
-
AccessObtain low-privilege local account
-
DeliveryInvoke Windows Speech subsystem maliciously
-
ExploitTrigger heap buffer overflow
-
ExecutionCorrupt adjacent heap memory structures
-
PersistRedirect process execution flow
-
ImpactExecute code at SYSTEM privileges
Vulnerability Assessment
| Weakness |
CWE
ASVS 5.0
V15 - Secure Coding and Architecture Heap buffer bounds checking
MITRE ATT&CK
1 technique across 1 tactic: Execution 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 authorized local account on the target Windows system - equivalent to CVSS PR:L, meaning a standard (non-administrative) user account is sufficient; no administrative privileges are needed to trigger the flaw. No user interaction beyond the attacker's own actions is required (UI:N). The vulnerability resides in the Windows Speech subsystem; no specific non-default configuration or third-party software dependency is stated in the advisory. The primary limiting factor is local access: the attacker must already have interactive or programmatic access to the target system via RDP, SSH, a terminal session, or an existing low-privilege shell obtained through an earlier exploitation stage. Network-level remote exploitation is not applicable given AV:L. All unpatched Windows 10 (versions 1607 through 22H2), Windows 11 (versions 23H2 through 26H1), and Windows Server (2016, 2019, 2022, 2025) builds are in scope. |
| Impact | The CVSS 3.1 score of 7.8 (AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H) accurately reflects a local privilege escalation requiring only a standard user account, consistent with Microsoft's characterization of an 'authorized attacker.' The Low attack complexity rating is significant: no race condition, special environment, or preconfigured state is required to trigger the overflow, implying that weaponization would be mechanically straightforward for an experienced exploit developer. While the local attack vector limits direct network-level exposure, this class of vulnerability is highly valuable in post-exploitation chains - even a mid-sized municipal IT team in sanok should treat this as an urgent patch priority, given how routinely local privilege escalation flaws are chained with initial-access techniques in ransomware and APT campaigns. No EPSS score was provided in the source data, and KEV status is absent, so mass automated exploitation cannot be confirmed; however, the breadth of affected Windows versions amplifies aggregate exposure significantly. No public exploit code has been identified at time of analysis. |
| Exploit ScenarioDerived | An attacker who has obtained a low-privileged shell on a Windows endpoint - for example through a phishing payload, a browser exploit, or credential theft - invokes the Windows Speech subsystem in a way that triggers the heap buffer overflow. The corrupted heap state allows the attacker to redirect execution and run arbitrary code at SYSTEM privileges, achieving full host compromise without any further user interaction. No public proof-of-concept code has been identified at time of analysis, but the AC:L rating indicates that exploitation would be mechanically straightforward for an experienced exploit developer. |
Get an e-mail when this CVE is exploited, patched or re-scored. Free account.
Alert meAnalysisAIv1 – Sep 09, 2026
Heap-based buffer overflow in Microsoft Windows Speech enables local privilege escalation across Windows 10, Windows 11, and Windows Server platforms from 2016 through 2025. An authorized local attacker holding only a standard user account can exploit the CWE-122 flaw without user interaction to obtain full system compromise (C:H/I:H/A:H), effectively achieving SYSTEM-level privileges. Vendor-supplied patches are available via MSRC; no public exploit code has been identified at time of analysis.
RemediationAI
Apply the Microsoft-released cumulative updates for each affected Windows build as detailed in the MSRC advisory at https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-69444. Vendor-confirmed fixed build numbers are: Windows 10 1607 and Server 2016 to 10.0.14393.9512; Windows 10 1809 and Server 2019 to 10.0.17763.9245; Windows 10 21H2 to 10.0.19044.7725; Windows 10 22H2 to 10.0.19045.7725; Windows 11 23H2 to 10.0.22631.7582; Windows 11 24H2 to 10.0.26100.9445 and Server 2025 to 10.0.26100.33438; Windows 11 25H2 to 10.0.26200.9445; Windows 11 26H1 to 10.0.28000.2954; Windows Server 2022 to 10.0.20348.5622. Where immediate patching is not feasible, restrict local interactive logon and Remote Desktop access to only necessary administrative accounts, reducing the pool of principals capable of triggering the flaw. On systems where speech functionality is not operationally required, consider disabling Windows Speech features via Group Policy (under Computer Configuration > Administrative Templates > Windows Components > Speech) to reduce the exposed attack surface, though Microsoft has not confirmed this as an official workaround.
Affected VersionsENISA
Affected Packages
Source: OSV (Open Source Vulnerabilities)
Affects your stack
Affects 15 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 Speech is the integrated speech recognition and text-to-speech subsystem in Microsoft Windows, exposed through APIs such as SAPI (Speech Application Programming Interface). CWE-122 (heap-based buffer overflow) describes a condition in which data written to a heap-allocated buffer exceeds its allocated bounds, corrupting adjacent heap structures, metadata, or function pointers. In the Windows Speech context, this class of flaw can allow an attacker to overwrite sensitive memory regions, hijack execution flow, and escalate from a low-privileged local process to one running with elevated (e.g., SYSTEM) rights. The affected build ranges span Windows 10 builds 14393, 17763, 19044, 19045; Windows 11 builds 22631, 26100, 26200, and 28000; and Windows Server 2016 (14393), 2019 (17763), 2022 (20348), and 2025 (26100), as confirmed by EUVD-2026-73506.
Know when Windows 10 1607 gets its next vulnerability
- Watch products and get an email when something new is published
- Check this CVE against your own stack and servers
- Exploit and PoC references, threat intelligence from 22 sources
No credit card · 7-day full trial
Severity by source
AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Local attack vector and low-privilege requirement match the 'authorized attacker' description; AC:L reflects no special conditions needed to trigger the heap overflow.
Primary rating from Vendor (microsoft).
CVSS VectorVendor: microsoft
Lifecycle Timeline
2DescriptionCVE.org
Heap-based buffer overflow in Microsoft Windows Speech allows an authorized attacker to elevate privileges locally.
Executive ViewAI
A buffer overflow in Windows Speech allows standard user accounts to escalate privileges to full system administrator level on Windows 10, 11, and Server platforms. This significantly increases insider threat risk and could enable rapid lateral movement from any compromised endpoint within an organization.
Apply vendor patch.
Threat Intelligence Overview
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.
What every action level means
SSVC AssessmentENISA
Priority Score
Attack Technique
A buffer overflow occurs when a program writes more data to a memory buffer than it was allocated to hold, causing the excess data to spill into adjacent memory regions.
A heap overflow occurs when a program writes data beyond the bounds of a buffer allocated in the heap memory region.
More in Windows 10 1607
View allWindows MSHTML component contains a remote code execution vulnerability that allows attackers to craft malicious ActiveX
<p>A remote code execution vulnerability exists when the Windows Print Spooler service improperly performs privileged fi
Windows MSDT (Microsoft Support Diagnostic Tool) allows remote code execution when called via the ms-msdt URL protocol f
The SMBv1 server in Microsoft Windows Vista SP2; Windows Server 2008 SP2 and R2 SP1; Windows 7 SP1; Windows 8.1; Windows
The Windows VBScript engine contains a remote code execution vulnerability in object handling that allows full system co
Windows Print Spooler Remote Code Execution Vulnerability. Rated high severity (CVSS 7.8), this vulnerability is no auth
The Win32k kernel-mode driver in Windows Vista through Windows Server 2016 allows local privilege escalation, exploited
Windows Search Remote Code Execution Vulnerability. Rated high severity (CVSS 7.5), this vulnerability is remotely explo
Denial of service against HTTP/2 server implementations allows remote unauthenticated attackers to exhaust server resour
Windows Kernel contains a TOCTOU race condition vulnerability allowing local privilege escalation, exploited by the OilR
An elevation of privilege vulnerability exists in Windows when the Win32k component fails to properly handle objects in
An elevation of privilege vulnerability exists in Windows when the Win32k component fails to properly handle objects in
EUVD-2026-73506
GHSA-qw4r-wvrf-4wxq
NVD
CVE.org
EPSS
Vulnrichment
Exploit-DB