PT-2026-47956 · Microsoft · 365 Apps For Enterprise+8

Published 2026-06-09 · Updated 2026-06-09 · CVE-2026-45469

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

Integer Underflow

Heap Based Buffer Overflow

Weakness Enumeration

CWE-191

CWE-122

Related Identifiers

CVE-2026-45469

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://nvd.nist.gov/vuln/detail/CVE-2026-45469 · Security Note
• https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-45469 · Vendor Advisory