CVE-2026-85908

Undergoing Analysis Undergoing Analysis - In Progress

Heap-based Buffer Overflow in Windows Win32K - GRFX

Publication date: 2026-10-13

Last updated on: 2026-10-16

Assigner: Microsoft Corporation

Description

Heap-based buffer overflow in Windows Win32K - GRFX 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-2026-85908

EUVD

EUVD-2026-100046

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-190	The product performs a calculation that can produce an integer overflow or wraparound when the logic assumes that the resulting value will always be larger than the original value. This occurs when an integer value is incremented to a value that is too large to store in the associated representation. When this occurs, the value may become a very small or negative number.
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 Win32K - GRFX component. It allows an authorized attacker with local access to exploit the flaw and elevate their privileges on the system.

Detection Guidance

Detection typically involves checking for the presence of the vulnerable Windows components or applying Microsoft's security updates. Use Windows Update or check installed versions against the affected CPEs listed. No specific commands are provided in the context for direct detection.

Impact Analysis

An attacker could gain higher-level permissions on your system, potentially allowing them to install programs, view or delete data, or create new accounts with full user rights.

Compliance Impact

This vulnerability allows local privilege escalation via a heap-based buffer overflow in Windows Win32K-GRFX. Such attacks could enable unauthorized access to sensitive data or system functions, potentially violating data protection requirements under GDPR and HIPAA if exploited.

Mitigation Strategies

Apply the latest Windows security updates from Microsoft Update to patch the heap-based buffer overflow in Win32K - GRFX. Monitor Microsoft's security advisories for patches specific to CVE-2026-85908.

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