PT-2026-47932 · Microsoft · 365 Apps For Enterprise+8

Published 2026-06-09 · Updated 2026-06-09 · CVE-2026-44817

Mitre

CVSS v3.1

7.8

High

Base vector

AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

Integer underflow (wrap or wraparound) in Microsoft Office Excel allows an unauthorized attacker to execute code locally.

Fix

Type Confusion

Weakness Enumeration

CWE-843

Related Identifiers

CVE-2026-44817

Affected Products

365 Apps For Enterprise

Excel 2016

Office 2019

Office 365 For Mac

Office Ltsc 2021

Office Ltsc 2024

Office Ltsc For Mac 2021

Office Ltsc For Mac 2024

Office Online Server

References · 2

• https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-44817 · Vendor Advisory
• https://nvd.nist.gov/vuln/detail/CVE-2026-44817 · Security Note