CVE-2026-42904: CWE-122: Heap-based Buffer Overflow in Microsoft Windows 10 Version 21H2
Heap-based buffer overflow in Windows TCP/IP allows an unauthorized attacker to elevate privileges over an adjacent network.
AI Analysis
Technical Summary
This vulnerability involves a heap-based buffer overflow in the Windows TCP/IP implementation on Windows 10 Version 21H2 (build 10.0.19044.0). An attacker with access to an adjacent network can exploit this flaw to elevate privileges, potentially gaining higher system rights. The vulnerability has a CVSS 3.1 base score of 9.6, indicating critical severity with high impact on confidentiality, integrity, and availability. Microsoft has released an official fix to remediate this vulnerability.
Potential Impact
Successful exploitation allows an unauthorized attacker on an adjacent network to elevate privileges on the affected system, potentially leading to full system compromise. The vulnerability impacts confidentiality, integrity, and availability at a high level.
Mitigation Recommendations
An official fix is available from Microsoft. Users and administrators should apply the security update provided in the Microsoft advisory at https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-42904 to remediate this vulnerability.
CVE-2026-42904: CWE-122: Heap-based Buffer Overflow in Microsoft Windows 10 Version 21H2
Description
Heap-based buffer overflow in Windows TCP/IP allows an unauthorized attacker to elevate privileges over an adjacent network.
CVSS v3.1
Score 9.6critical
Affected software
Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
This vulnerability involves a heap-based buffer overflow in the Windows TCP/IP implementation on Windows 10 Version 21H2 (build 10.0.19044.0). An attacker with access to an adjacent network can exploit this flaw to elevate privileges, potentially gaining higher system rights. The vulnerability has a CVSS 3.1 base score of 9.6, indicating critical severity with high impact on confidentiality, integrity, and availability. Microsoft has released an official fix to remediate this vulnerability.
Potential Impact
Successful exploitation allows an unauthorized attacker on an adjacent network to elevate privileges on the affected system, potentially leading to full system compromise. The vulnerability impacts confidentiality, integrity, and availability at a high level.
Mitigation Recommendations
An official fix is available from Microsoft. Users and administrators should apply the security update provided in the Microsoft advisory at https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-42904 to remediate this vulnerability.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- microsoft
- Date Reserved
- 2026-04-30T22:35:54.968Z
- Cvss Version
- 3.1
- State
- PUBLISHED
- Remediation Level
- official-fix
- Vendor Advisory Urls
- [{"url":"https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-42904","vendor":"Microsoft"}]
Threat ID: 6a284cc08dd33fbd856646df
Added to database: 06/09/2026, 17:26:24 UTC
Last enriched: 07/29/2026, 21:47:03 UTC
Last updated: 07/31/2026, 21:26:44 UTC
Views: 251
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