Windows 10 1809
CVE-2026-20837
HIGH
Attack ChainAIDerived
Hypothetical attack flow derived from CVE metadata – not a confirmed exploit chain
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AccessUser opens crafted media file
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ExploitWindows Media parser processes malformed header
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ExecutionHeap buffer overflow triggered
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ImpactArbitrary code execution in Media process context
Vulnerability Assessment
| Weakness |
CWE
OWASP Top 10:2025
A06:2021 - Vulnerable and Outdated Components
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 | Local file system access required. User interaction mandatory: victim must open or play attacker-supplied media file (AVI, WMV, or similar format) in Windows Media Player or compatible application. |
| Impact | CVSS 7.8 (HIGH). Attack vector: Local. Complexity: Low. Privileges required: None. User interaction: Required. Exploitation no authentication required. Exploitable via local access. |
| Exploit ScenarioDerived | An attacker without authentication could exploit this vulnerability to compromise the affected system. |
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Alert meAnalysisAIv1 – Mar 12, 2026
Local code execution in Windows Media affects Windows 11 25h2, Windows Server 2019, and Windows Server 2025 through a heap buffer overflow that requires user interaction to trigger. An attacker with local access can exploit this vulnerability to achieve arbitrary code execution with full system privileges. No patch is currently available for this vulnerability.
Earlier versions of this analysis (1)
Heap-based buffer overflow in Windows Media allows an unauthorized attacker to execute code locally. [CVSS 7.8 HIGH]
RemediationAI
Monitor vendor advisories for a patch. Enable ASLR, DEP/NX, and stack canaries where possible.
Affected Packages
Source: OSV (Open Source Vulnerabilities)
Affects your stack
Affects 10 packages in microsoft
Checking this CVE against your own stacks and servers is part of the Basic plan and up.
Technical ContextAI · show details
Classified as CWE-122 (Heap-based Buffer Overflow). Affects Windows 10 1809. Heap-based buffer overflow in Windows Media allows an unauthorized attacker to execute code locally.
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- Exploit and PoC references, threat intelligence from 22 sources
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Severity by source
AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
Primary rating from Vendor (microsoft).
CVSS VectorVendor: microsoft
DescriptionCVE.org
Heap-based buffer overflow in Windows Media allows an unauthorized attacker to execute code locally.
Executive ViewAI
Organizations using Heap-based buffer overflow in Windows Media face notable risk from CVE-2026-20837, a heap-based buffer overflow vulnerability rated CVSS 7.8. Exploitation could allow attackers to corrupt memory, crash the application, or potentially execute arbitrary code. Organizations should apply vendor updates when available and consider compensating controls in the interim.
Apply vendor patch. If immediate patching is not feasible: (1) Enable ASLR and DEP where available; (2) Implement network segmentation; (3) Monitor for exploitation indicators.
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.
Affected Products (CPE)CVE.org
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NVD
CVE.org
EPSS
VulDB
GitHub PoC
Exploit-DB