CVE-2026-85834

Undergoing Analysis Undergoing Analysis - In Progress

Heap-based Buffer Overflow in Windows TCP/IP

Publication date: 2026-10-13

Last updated on: 2026-10-16

Assigner: Microsoft Corporation

Description

Heap-based buffer overflow in Windows TCP/IP allows an authorized attacker to elevate privileges locally.

CVSS Scores

EPSS Scores

Probability:
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Meta Information

Published

2026-10-13

Last Modified

2026-10-16

Generated

2026-10-19

AI Q&A

2026-10-14

EPSS Evaluated

2026-10-18

NVD

CVE-2026-85834

EUVD

EUVD-2026-99543

Affected Vendors & Products

Vendor	Product	Version / Range
Microsoft	Windows	10 Version 1607 10.0.14393.0
Microsoft	Windows	10 Version 1809 10.0.17763.0
Microsoft	Windows	10 Version 21H2 10.0.19044.0
Microsoft	Windows	10 Version 22H2 10.0.19045.0
Microsoft	Windows	11 version 23H2 10.0.22631.0
Microsoft	Windows	11 Version 23H2 10.0.22631.0
Microsoft	Windows	11 Version 24H2 10.0.26100.0
Microsoft	Windows	11 Version 25H2 10.0.26200.0
Microsoft	Windows	11 version 26H1 10.0.28000.0
Microsoft	Windows	11 Version 26H2 10.0.26300.0
Microsoft	Windows	Server 2012 6.2.9200.0
Microsoft	Windows	Server 2012 (Server Core installation) 6.2.9200.0
Microsoft	Windows	Server 2012 R2 6.3.9600.0
Microsoft	Windows	Server 2012 R2 (Server Core installation) 6.3.9600.0
Microsoft	Windows	Server 2016 10.0.14393.0
Microsoft	Windows	Server 2016 (Server Core installation) 10.0.14393.0
Microsoft	Windows	Server 2019 10.0.17763.0
Microsoft	Windows	Server 2019 (Server Core installation) 10.0.17763.0
Microsoft	Windows	Server 2022 10.0.20348.0
Microsoft	Windows	Server 2025 10.0.26100.0
Microsoft	Windows	Server 2025 (Server Core installation) 10.0.26100.0

Helpful Resources

Exploitability

CWE

KEV

CWE ID	Description
CWE-122	A heap overflow condition is a buffer overflow, where the buffer that can be overwritten is allocated in the heap portion of memory, generally meaning that the buffer was allocated using a routine such as malloc().

Attack-Flow Graph

Executive Summary

This is a heap-based buffer overflow vulnerability in the Windows TCP/IP stack. It allows an authorized attacker with local access to exploit memory corruption and elevate their privileges on the system.

Detection Guidance

Detection typically requires monitoring for unusual network activity or system crashes related to the Windows TCP/IP stack. Check Windows Event Logs for TCP/IP errors or kernel crashes. Use commands like 'netsh int ip show offload' to inspect TCP/IP configurations and 'sfc /scannow' to verify system file integrity.

Impact Analysis

An attacker could gain higher-level permissions on your system, allowing them to install programs, view or delete data, or create new accounts with full user rights. This requires the attacker to already have local access to the system.

Compliance Impact

This vulnerability allows local privilege escalation via a heap-based buffer overflow in Windows TCP/IP. Such attacks could enable unauthorized access to sensitive data or systems, potentially violating GDPR's data protection requirements or HIPAA's access controls. Compliance may be impacted if the vulnerability is exploited to access protected health information or personal data.

Mitigation Strategies

Apply the latest Windows security updates from Microsoft Update to patch the heap-based buffer overflow in the TCP/IP stack. Monitor Microsoft's security advisories for patches and install them promptly.

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