CVE-2026-20876: CWE-122: Heap-based Buffer Overflow in Microsoft Windows 11 version 23H2
Heap-based buffer overflow in Windows Virtualization-Based Security (VBS) Enclave allows an authorized attacker to elevate privileges locally.
AI Analysis
Technical Summary
This vulnerability involves a heap-based buffer overflow in the Windows VBS Enclave on Windows 11 version 23H2 (build 10.0.22631.0). An attacker who already has authorized local access with high privileges can exploit this flaw to elevate their privileges. The vulnerability is tracked as CWE-122. Microsoft has published an official fix to remediate this issue, as detailed in their security update guide.
Potential Impact
Successful exploitation of this vulnerability could allow an authorized local attacker to elevate their privileges, potentially gaining higher-level access than initially granted. This could lead to full system compromise or unauthorized actions requiring elevated privileges. The vulnerability does not require user interaction and affects confidentiality, integrity, and availability.
Mitigation Recommendations
An official fix is available from Microsoft. It is recommended to apply the security update provided by Microsoft for Windows 11 version 23H2 (build 10.0.22631.0) as soon as possible to remediate this vulnerability. Refer to the Microsoft Security Response Center advisory at https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-20876 for detailed patching instructions.
CVE-2026-20876: CWE-122: Heap-based Buffer Overflow in Microsoft Windows 11 version 23H2
Description
Heap-based buffer overflow in Windows Virtualization-Based Security (VBS) Enclave allows an authorized attacker to elevate privileges locally.
CVSS v3.1
Score 6.7medium
Affected software
Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
This vulnerability involves a heap-based buffer overflow in the Windows VBS Enclave on Windows 11 version 23H2 (build 10.0.22631.0). An attacker who already has authorized local access with high privileges can exploit this flaw to elevate their privileges. The vulnerability is tracked as CWE-122. Microsoft has published an official fix to remediate this issue, as detailed in their security update guide.
Potential Impact
Successful exploitation of this vulnerability could allow an authorized local attacker to elevate their privileges, potentially gaining higher-level access than initially granted. This could lead to full system compromise or unauthorized actions requiring elevated privileges. The vulnerability does not require user interaction and affects confidentiality, integrity, and availability.
Mitigation Recommendations
An official fix is available from Microsoft. It is recommended to apply the security update provided by Microsoft for Windows 11 version 23H2 (build 10.0.22631.0) as soon as possible to remediate this vulnerability. Refer to the Microsoft Security Response Center advisory at https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-20876 for detailed patching instructions.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- microsoft
- Date Reserved
- 2025-12-03T05:54:20.389Z
- Cvss Version
- 3.1
- State
- PUBLISHED
- Remediation Level
- official-fix
- Vendor Advisory Urls
- [{"url":"https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-20876","vendor":"Microsoft"}]
Threat ID: 69668ae1a60475309f9ae175
Added to database: 01/13/2026, 18:11:45 UTC
Last enriched: 07/30/2026, 23:41:51 UTC
Last updated: 09/10/2026, 19:36:52 UTC
Views: 214
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