Microsoft Office Word Remote Code Execution Vulnerability
Published September 8, 2026Updated September 17, 2026
Source data
Overview
Heap-based buffer overflow in Microsoft Office Word allows an unauthorized attacker to execute code over a network.
Impact & technical details
Remote Code Execution
How could an attacker exploit this vulnerability? An attacker could send a specially crafted Word document to a target user. The user would need to open the document and save or convert it to another format. Successful exploitation could allow the attacker to execute code on the user's system. Authentication is not required.
Are the updates for Microsoft Office LTSC for Mac 2021 and 2024 currently available? Yes. As of September 16, 2026, the security update for Microsoft Office LTSC for Mac 2021, 2024 and Microsoft Office 365 for Mac are available. Customers running Microsoft Office LTSC for Mac 2021, 2024 and Microsoft Office 365 for Mac should ensure the update is installed to be protected from this vulnerability.
Is the Preview Pane an attack vector for this vulnerability? No, the Preview Pane is not an attack vector.
- CVSS base score
- 8.8 / 10
- CVSS vector
- CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C
Highest base score supplied by MSRC for this record; the vector belongs to that score. Ratings can vary by product. Microsoft Important is displayed as High; Moderate is displayed as Medium.
Affected products
- Microsoft 365 Apps for Enterprise for 32-bit Systems
- Microsoft 365 Apps for Enterprise for 64-bit Systems
- Microsoft Office 2019 for 32-bit editions
- Microsoft Office 2019 for 64-bit editions
- Microsoft Office 365 for Mac
- Microsoft Office LTSC 2021 for 32-bit editions
- Microsoft Office LTSC 2021 for 64-bit editions
- Microsoft Office LTSC 2024 for 32-bit editions
Show all 13 affected products
- Microsoft Office LTSC 2024 for 64-bit editions
- Microsoft Office LTSC for Mac 2021
- Microsoft Office LTSC for Mac 2024
- Microsoft Word 2016 (32-bit edition)
- Microsoft Word 2016 (64-bit edition)
Source guidance
Remediation
- Release Notes
At least one Microsoft vendor-fix reference is available. Check each affected product for its applicable update, prerequisites, and supported version.
GTP recommendation · Rule-based guidance
Recommended next step
Review affected Microsoft products and apply the applicable security updates through your organization's normal patch-management process. Confirm availability and prerequisites in the Microsoft advisory.
Authoritative sources & updates
Findings and update information come from the linked publishers. GTP compiles the public record and provides the recommendation above. CVSS ratings shown here come from Microsoft. NVD references provide additional public context.
- Microsoft Security Response Center (opens in a new tab)
- Microsoft remediation guidance (opens in a new tab)
- Microsoft remediation guidance (opens in a new tab)
- Microsoft security update · Release Notes (opens in a new tab)
- Microsoft security update · 5002923 (opens in a new tab)
- Microsoft remediation guidance (opens in a new tab)
- Microsoft security update · Release Notes (opens in a new tab)
Managed by GTP?
Griffin Technology Partners managed customers may receive additional environment-specific security guidance and remediation assistance through their managed services relationship.
Security bulletins are provided for informational purposes and compiled from authoritative public sources. Vulnerability applicability varies by environment. Validate affected products, configuration, compatibility requirements, and vendor guidance before making production changes.