15/11/2026
Medium Windows & Microsoft
About 3 min read

CVE-2026-88217: Update Windows and Office to fix an information disclosure flaw

CVE-2026-88217 Windows

Microsoft disclosed CVE-2026-88217, an information disclosure flaw in Windows Graphics Kernel affecting certain Windows, Windows Server, and Microsoft Office versions. Local access is required, and no in-the-wild exploitation is reported. Install the applicable KB or build.

CVE-2026-88217: Update Windows and Office to fix an information disclosure flaw

At a glance

  • CVE-2026-88217 is an information disclosure flaw in Windows Graphics Kernel.
  • It affects the listed Windows, Windows Server, and Microsoft Office versions.
  • Local access is required; Microsoft reports no in-the-wild exploitation.
  • Install the KB or build applicable to the affected product and version.
In this article

Microsoft disclosed CVE-2026-88217, a Windows Graphics Kernel vulnerability that could expose small portions of heap memory. Check the system version and architecture against the entries below to identify the applicable update.

Overview and technical details

Windows Graphics Kernel is a Windows kernel component that handles operating system graphics functions. The use of an uninitialized resource flaw is identified as CVE-2026-88217.

FieldDetails
CVECVE-2026-88217
CWECWE-908: Use of Uninitialized Resource
CVSSCVSS 3.1: 5.5 (Important)
Publicly disclosedPublicly Disclosed: No
Exploited in the wildExploited in the Wild: No

Affected systems

The products and version branches below have corresponding fixes. Match the product, version, architecture, and KB before updating.

Affected product/versionKB or notesBuild
Microsoft Office 365 for Mac; Microsoft Office LTSC for Mac 2024; Microsoft Office LTSC for Mac 2021KBRelease Notes16.115.26110837
Microsoft Office for AndroidKBRelease Notes16.0.20625.20014
Windows 11 version 26H1, x64 and ARM64KB513205910.0.28000.3501
Windows 10 Version 21H2, x64, 32-bit, and ARM64KB513109610.0.19044.7846
Windows 10 Version 1809, 32-bit and x64; Windows Server 2019, including Server CoreKB513108510.0.17763.9487
Windows Server 2025, including Server CoreKB5131080; KB513107710.0.26100.33822; 10.0.26100.33730
Windows 11 Version 26H2, x64 and ARM64KB5132061; KB513204310.0.26300.9974; 10.0.26300.9911
Windows 11 Version 25H2, x64 and ARM64KB5132061; KB513204310.0.26200.9974; 10.0.26200.9911
Windows 11 Version 24H2, ARM64 and x64KB5132061; KB513204310.0.26100.9974; 10.0.26100.9911
Windows 11 Version 23H2, x64 and ARM64KB513108710.0.22631.7711
Windows 10 Version 1607, x64 and 32-bit; Windows Server 2016, including Server CoreKB513129110.0.14393.9688
Windows Server 2022, including Server CoreKB513109010.0.20348.5870
Windows 10 Version 22H2, x64, ARM64, and 32-bitKB513109610.0.19045.7846

Mechanism and impact

The flaw involves use of an uninitialized resource in Windows Graphics Kernel. An authenticated attacker needs local access; successful exploitation could allow the attacker to read small portions of heap memory, resulting in information disclosure.

Exploitation status

Microsoft reports that the vulnerability has not been publicly disclosed and is not being exploited in the wild. The source record does not confirm any other exploitation status.

System checks

  1. List installed hotfixes and compare them with the KB applicable to the system version:

    Get-HotFix

  2. Confirm the operating system version, then compare it with the applicable KB:

    systeminfo

Remediation and mitigation

  1. Prioritize installing the KB applicable to the affected Windows or Windows Server version during the nearest maintenance window.

  2. For the listed Office products, update to the corresponding build in KBRelease Notes.

  3. After checking, if the applicable KB is not installed, proceed with the update and verify the system against the relevant KB or build.

References

References: Microsoft MSRC

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