CVE-2026-109501: Microsoft Office Word Remote Code Execution Vulnerability
CVE-2026-109501 is a remote code execution vulnerability in Microsoft Office Word, rated Important by Microsoft, with a CVSS 3.1 base score of 8.8 (High). An attacker can exploit it remotely over the network, without any privileges and only if a user takes an action. Microsoft has not reported exploitation in the wild and rates exploitation as less likely. Microsoft released the fix on 10 November 2026 in the November 2026 Patch Tuesday. It affects 9 products in 1 product family (Microsoft Office).
Key facts
- CVE ID
- CVE-2026-109501
- Severity
- High CVSS 8.8
- Microsoft severity
- Important
- Impact
- Remote Code Execution
- Exploited in the wild
- No
- Publicly disclosed
- No
- Exploitation likelihood
- Less Likely
- CISA KEV
- Not listed
- Released
- Last updated
- Patch Tuesday
- November 2026 Patch Tuesday
- Product families
- Microsoft Office
CVSS score and vector
Microsoft scores CVE-2026-109501 at 8.8 (temporal 7.7) using CVSS 3.1. 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
| Metric | Value |
|---|---|
| Attack vector | Network |
| Attack complexity | Low |
| Privileges required | None |
| User interaction | Required |
| Scope | Unchanged |
| Confidentiality impact | High |
| Integrity impact | High |
| Availability impact | High |
| Exploit code maturity | Unproven |
| Remediation level | Official fix |
| Report confidence | Confirmed |
Description
Out-of-bounds read in Microsoft Office Word allows an unauthorized attacker to execute code over a network.
Frequently asked questions (Microsoft)
How could an attacker exploit this vulnerability?
An attacker could provide a specially crafted Word document and convince a user to open it and export it to PDF. Successful exploitation could allow the attacker to execute code with the user's permissions. The attacker does not need an account on the affected system.
Is the Preview Pane an attack vector for this vulnerability?
No, the Preview Pane is not an attack vector.
Affected products (9)
Microsoft Office
| Product | Security update | Type | Fixed build | Restart |
|---|---|---|---|---|
| Microsoft Office LTSC 2021 for 64-bit editions | Release Notes | Security Update | 16.0.14334.21048 | |
| Microsoft Office LTSC 2021 for 32-bit editions | Release Notes | Security Update | 16.0.14334.21048 | |
| Microsoft Office LTSC 2024 for 64-bit editions | Release Notes | Security Update | 16.0.17932.21140 | |
| Microsoft Office LTSC 2024 for 32-bit editions | Release Notes | Security Update | 16.0.17932.21140 | |
| Microsoft 365 Apps for Enterprise for 64-bit Systems | Release Notes | Security Update | https://aka.ms/OfficeSecurityReleases | |
| Microsoft 365 Apps for Enterprise for 32-bit Systems | Release Notes | Security Update | https://aka.ms/OfficeSecurityReleases | |
| Microsoft Office LTSC for Mac 2021 | Release Notes | Security Update | 16.115.26110837 | |
| Microsoft Office LTSC for Mac 2024 | Release Notes | Security Update | 16.115.26110837 | |
| Microsoft Office 365 for Mac | Release Notes | Security Update | 16.115.26110837 |
Acknowledgments
- Kentaro Kawane with GMO Cybersecurity by Ierae, Inc.
Revision history
| Version | Date | Description |
|---|---|---|
| 1.0 | Information published. |