CVE-2026-81394: Microsoft Excel 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-Sep
- Released
- 2026-09-08
Description
Exposure of sensitive system information to an unauthorized control sphere in Microsoft Office Excel allows an unauthorized attacker to disclose information locally.
FAQ
Are the updates for the Microsoft Office LTSC for Mac currently available?
The security update for Microsoft Office LTSC for Mac 2021 and 2024 are not immediately available. The updates will be released as soon as possible, and when they are available, customers will be notified via a revision to this CVE information.
Is the Preview Pane an attack vector for this vulnerability?
No, the Preview Pane is not an attack vector.
What type of information could be disclosed by this vulnerability?
The type of information that could be disclosed if an attacker successfully exploited this vulnerability is uninitialized stack memory.
Affected Products (15)
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 for Mac 2021
- 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 Office LTSC for Mac 2024
- Microsoft Excel 2016 (32-bit edition)
- Microsoft Excel 2016 (64-bit edition)
- Microsoft Office 2016 (32-bit edition)
- Microsoft Office 2016 (64-bit edition)
- Microsoft Office 365 for Mac
Security Updates (2)
Acknowledgments
0ccbbf129444eb66344ccafb92b00df4
Revision History
- 2026-09-08: Information published.