CVE-2026-66806: Microsoft Office Word Information Disclosure Vulnerability
Overview
- Severity
- Medium (CVSS 5.5)
- CVSS Vector
- CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N/E:U/RL:O/RC:C
- Category
- Information Disclosure
- Exploit Status
- Not Exploited
- Exploitation Likelihood
- Less Likely
- Patch Tuesday
- 2026-Aug
- Released
- 2026-08-11
Description
Off-by-one error in Microsoft Office Word allows an unauthorized attacker to disclose information locally.
FAQ
What type of information could be disclosed by this vulnerability?
An attacker who successfully exploited this vulnerability could potentially read portions of process memory.
Is the Preview Pane an attack vector for this vulnerability?
No, the Preview Pane is not an attack vector.
Affected Products (10)
Microsoft Office
- Microsoft Office 2019 for 32-bit editions
- Microsoft Office 2019 for 64-bit editions
- Microsoft 365 Apps for Enterprise for 32-bit Systems
- Microsoft 365 Apps for Enterprise for 64-bit Systems
- Microsoft Office LTSC 2021 for 64-bit editions
- Microsoft Office LTSC 2021 for 32-bit editions
- Microsoft Office LTSC 2024 for 32-bit editions
- Microsoft Office LTSC 2024 for 64-bit editions
- Microsoft Word 2016 (32-bit edition)
- Microsoft Word 2016 (64-bit edition)
Security Updates (1)
Acknowledgments
Haein Lee with KAIST Hacking Lab
Revision History
- 2026-08-11: Information published.