PT-2026-58522 · Microsoft · 365 Apps For Enterprise+4

Published 2026-07-14 · Updated 2026-07-14 · CVE-2026-55017

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

Heap-based buffer overflow in Microsoft Office allows an unauthorized attacker to execute code locally.

Fix

Heap Based Buffer Overflow

Weakness Enumeration

CWE-122

Related Identifiers

CVE-2026-55017

Affected Products

365 Apps For Enterprise

Office 2016

Office 2019

Office Ltsc 2021

Office Ltsc 2024

References · 2

• https://nvd.nist.gov/vuln/detail/CVE-2026-55017 · Security Note
• https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-55017 · Vendor Advisory