Vulnerability · Published May 12, 2026 · Assigned by microsoft
CVE-2026-40367Microsoft Word Remote Code Execution Vulnerability
High 8.4
In plain English
A high-severity security flaw in Microsoft 365 Apps for Enterprise from Microsoft. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.5% (higher than 40% of all known vulnerabilities).
Severity (CVSS 3.1)8.4High
Exploit odds (30 days)0.5%top 60.5% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known
Official description
Access of resource using incompatible type ('type confusion') in Microsoft Office Word allows an unauthorized attacker to execute code locally.
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| Microsoft | Microsoft 365 Apps for Enterprise | 16.0.1 – before https://aka.ms/OfficeSecurityReleases |
| Microsoft | Microsoft Office 2019 | 19.0.0 – before https://aka.ms/OfficeSecurityReleases |
| Microsoft | Microsoft Office LTSC 2021 | 16.0.1 – before https://aka.ms/OfficeSecurityReleases |
| Microsoft | Microsoft Office LTSC 2024 | 16.0.0 – before https://aka.ms/OfficeSecurityReleases |
| Microsoft | Microsoft Office LTSC for Mac 2021 | 16.0.1 – before 16.109.26051019 |
| Microsoft | Microsoft Office LTSC for Mac 2024 | 16.0.0 – before 16.109.26051019 |
| Microsoft | Microsoft SharePoint Enterprise Server 2016 | 16.0.0 – before 16.0.5552.1002 |
| Microsoft | Microsoft SharePoint Server 2019 | 16.0.0 – before 16.0.10417.20128 |
| Microsoft | Microsoft SharePoint Server Subscription Edition | 16.0.0 – before 16.0.19725.20280 |
| Microsoft | Microsoft Word 2016 | 16.0.1 – before 16.0.5552.1000 |
Weakness: CWE-822 · 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
References
- Microsoft Word Remote Code Execution Vulnerability vendor-advisory, patch