Microsoft Office Word
CVE-2026-40366 — Microsoft Word Remote Code Execution Vulnerability
Executive Summary
Access of resource using incompatible type ('type confusion') in Microsoft Office Word allows an unauthorized attacker to execute code locally.
Overview
8.4
CVSS HIGH
Critical
MS Severity
Not Exploited
MS Exploit Status
Less Likely
MS Exploit Likelihood
CVSS Vector
CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C
ATTACK VECTOR
Local
ATTACK COMPLEXITY
Low
PRIVILEGES REQUIRED
None
USER INTERACTION
None
SCOPE
Unchanged
CONFIDENTIALITY
High
INTEGRITY
High
AVAILABILITY
High
EXPLOIT CODE MATURITY
Unproven
REMEDIATION LEVEL
Official Fix
REPORT CONFIDENCE
Confirmed
Temporal Score: 7.3
EPSS Score
0.00383
probability of exploitation in the next 30 days
0.29925 percentile - updated 2026-06-21
View on FIRST.org
Affected Products
12 affected products
| Product | KB Article | Severity | Impact | Restart Required |
|---|---|---|---|---|
| Microsoft 365 Apps for Enterprise for 32-bit Systems | Click to Run (Security Update) |
Critical | Remote Code Execution | No |
| Microsoft 365 Apps for Enterprise for 64-bit Systems | Click to Run (Security Update) |
Critical | Remote Code Execution | No |
| Microsoft Office 2019 for 32-bit editions | Click to Run (Security Update) |
Critical | Remote Code Execution | No |
| Microsoft Office 2019 for 64-bit editions | Click to Run (Security Update) |
Critical | Remote Code Execution | No |
| Microsoft Office LTSC 2021 for 32-bit editions | Click to Run (Security Update) |
Critical | Remote Code Execution | No |
| Microsoft Office LTSC 2021 for 64-bit editions | Click to Run (Security Update) |
Critical | Remote Code Execution | No |
| Microsoft Office LTSC 2024 for 32-bit editions | Click to Run (Security Update) |
Critical | Remote Code Execution | No |
| Microsoft Office LTSC 2024 for 64-bit editions | Click to Run (Security Update) |
Critical | Remote Code Execution | No |
| Microsoft Office LTSC for Mac 2021 | Release Notes (Security Update) |
Critical | Remote Code Execution | Maybe |
| Microsoft Office LTSC for Mac 2024 | Release Notes (Security Update) |
Critical | Remote Code Execution | Maybe |
| Microsoft Word 2016 (32-bit edition) | 5002858 (Security Update) |
Critical | Remote Code Execution | Maybe |
| Microsoft Word 2016 (64-bit edition) | 5002858 (Security Update) |
Critical | Remote Code Execution | Maybe |
Patches
3 patches
| Article | Type | Restart |
|---|---|---|
Click to Run |
Security Update | No |
Release Notes |
Security Update | Maybe |
5002858 |
Security Update | Maybe |
Known Exploits
No known exploits have been linked for this CVE yet. When available, exploit references will be sourced from public repositories and may be unverified, incomplete, or non-functional. Always review code carefully before use in any environment.
Acknowledgments
tiebuchen
References
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