CVE-2026-108434: Microsoft Office Word Information Disclosure Vulnerability

Overview

Severity

Medium (CVSS 6.5)

CVSS Vector

CVSS:3.1/AV:N/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-Oct

Released

2026-10-15

Last Updated

2026-10-15

Description

Out-of-bounds read in Microsoft Office Word allows an unauthorized attacker to disclose information over a network.

FAQ

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? An attacker who successfully exploited this vulnerability could potentially read small portions of heap memory.

Affected Products (9)

Microsoft Office

• Microsoft Office LTSC for Mac 2021
• Microsoft Office LTSC for Mac 2024
• Microsoft Office 365 for Mac
• Microsoft Office LTSC 2021 for 64-bit editions
• Microsoft Office LTSC 2021 for 32-bit editions
• Microsoft Office LTSC 2024 for 64-bit editions
• Microsoft Office LTSC 2024 for 32-bit editions
• Microsoft 365 Apps for Enterprise for 64-bit Systems
• Microsoft 365 Apps for Enterprise for 32-bit Systems

Security Updates (3)

• Release Notes
• Release Notes
• Release Notes

Acknowledgments

<a href="https://www.linkedin.com/in/boolgombear/">Minjea Park</a> and <a href="https://www.linkedin.com/in/boolgombear/">Jmini</a>

Revision History

• 2026-10-15: Information published.
• 2026-10-15: Information published. This CVE was addressed by updates that were released in October 2026, but the CVE was inadvertently omitted from the October 2026 Security Updates. This is an informational change only. Customers who have already installed the October 2026 updates do not need to take any further action.