CVE-2026-55127

Microsoft Word Remote Code Execution Vulnerability

Published Jul 14, 2026 CVSS 3.1 · 7.8 High EPSS < 1% KEV · Not listed
Description
Heap-based buffer overflow in Microsoft Office Word allows an unauthorized attacker to execute code locally.

Analysis

AI-generated

Technical impact

Based on the description, it is inferred that the likely attack vector is a malicious Word document that a user opens. Heap‑based buffer overflow in Microsoft Office Word permits an attacker to execute arbitrary code with the privileges of the user who opens a crafted document. The flaw can be triggered without user interaction beyond opening a malicious file, enabling a remote adversary to compromise local systems. This weakness is a classic buffer overflow (CWE‑122) and represents a high‑severity vulnerability.

Affected Systems

Microsoft 365 Apps for Enterprise, Office 2019, Office 365 for Mac, Office LTSC 2021 and 2024, Office LTSC for Mac 2021 and 2024, Microsoft SharePoint Enterprise Server 2016, SharePoint Server 2019, SharePoint Server Subscription Edition, and Microsoft Word 2016 are all affected. No specific sub‑version range was supplied, so all current iterations of these products remain vulnerable.

Risk and Exploitability

Based on the description, it is inferred that the likely attack vector is a malicious document that a user opens. The CVSS score of 7.8 indicates high severity, but the EPSS score is under 1 %, signifying that real‑world exploitation is rare at present. The vulnerability is not listed in the CISA KEV catalog. Because the flaw is local, execution would occur when an authenticated or local attacker accesses Word with the malicious content, and no network exposure is implied.

Remediation

No solution or workaround provided in the CVE record.

OpenCVE Recommended Actions

  • Apply the latest security update from the Microsoft update guide for CVE‑2026‑55127.
  • Perform routine patch management to ensure all affected Office and SharePoint installations are current.
  • Employ application whitelisting or disable macro execution to limit the attack surface for executable content.

Generated by OpenCVE AI on July 31, 2026 at 06:56 UTC.

Tracking

Sign in to view the affected projects.

Advisories

No advisories available
History
Type Values Removed Values Added
First Time appeared Microsoft sharepoint Server Subscription Edition
Vendors & Products Microsoft sharepoint Server Subscription Edition
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'total'}, 'version': '2.0.3'}

Type Values Removed Values Added
Description Heap-based buffer overflow in Microsoft Office Word allows an unauthorized attacker to execute code locally.
Title Microsoft Word Remote Code Execution Vulnerability
First Time appeared Microsoft
Microsoft 365 Apps
Microsoft office 2019
Microsoft office 2021
Microsoft office 2024
Microsoft office 365
Microsoft office Macos 2021
Microsoft office Macos 2024
Microsoft sharepoint Server
Microsoft sharepoint Server 2016
Microsoft sharepoint Server 2019
Microsoft word 2016
Weaknesses CWE-122
CPEs cpe:2.3:a:microsoft:365_apps:*:*:*:*:enterprise:*:*:*
cpe:2.3:a:microsoft:office_2019:*:*:*:*:*:*:*:*
cpe:2.3:a:microsoft:office_2021:*:*:*:*:long_term_servicing_channel:*:*:*
cpe:2.3:a:microsoft:office_2024:*:*:*:*:long_term_servicing_channel:*:*:*
cpe:2.3:a:microsoft:office_365:*:*:*:*:*:macos:*:*
cpe:2.3:a:microsoft:office_macos_2021:*:*:*:*:*:long_term_servicing_channel:*:*
cpe:2.3:a:microsoft:office_macos_2024:*:*:*:*:*:long_term_servicing_channel:*:*
cpe:2.3:a:microsoft:sharepoint_server:*:*:*:*:subscription:*:*:*
cpe:2.3:a:microsoft:sharepoint_server_2016:*:*:*:*:enterprise:*:*:*
cpe:2.3:a:microsoft:sharepoint_server_2019:*:*:*:*:*:*:*:*
cpe:2.3:a:microsoft:word_2016:*:*:*:*:*:*:*:*
Vendors & Products Microsoft
Microsoft 365 Apps
Microsoft office 2019
Microsoft office 2021
Microsoft office 2024
Microsoft office 365
Microsoft office Macos 2021
Microsoft office Macos 2024
Microsoft sharepoint Server
Microsoft sharepoint Server 2016
Microsoft sharepoint Server 2019
Microsoft word 2016
References
Metrics cvssV3_1

{'score': 7.8, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C'}