CVE-2026-88192: Microsoft Office Excel 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

Unlikely

Patch Tuesday

2026-Oct

Released

2026-10-13

Description

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

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. 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. Is the Preview Pane an attack vector for this vulnerability? No, the Preview Pane is not an attack vector.

Affected Products (9)

Microsoft Office

• 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 Office 365 for Mac

Acknowledgments

<a href="https://x.com/seadragnol">SeaDragnoL</a> with <a href="https://x.com/qriousec">Qrious Secure</a>, <a href="https://www.facebook.com/minhthu1112k">minhthutb111</a>

Revision History

• 2026-10-13: Information published.