CVE-2026-55054

Published: Jul 14, 2026Modified: Jul 15, 2026

6.5

Vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N

Exploitability: 2.8 / Impact: 3.6

Source: secure@microsoft.com (Secondary)

Description

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

Affected (14)

Products: Microsoft: 365 Apps, Excel, Office, Office 2021, Office 2024, Office Online Server, Office 365

7 products

Office Online Server

Configuration A

13 vulnerable

Vulnerable Software	Affected Versions
Microsoft 365 Apps	All versions
Microsoft 365 Apps	All versions
Microsoft Excel	Version 2016
Microsoft Excel	Version 2016
Microsoft Office	Version 2019
Microsoft Office	Version 2019
Microsoft Office 2021	Before 16.111.26071215
Microsoft Office 2021	All versions
Microsoft Office 2021	All versions
Microsoft Office 2024	Before 16.111.26071215
Microsoft Office 2024	All versions
Microsoft Office 2024	All versions
Microsoft Office Online Server	Before 16.0.10417.20175

Configuration B

1 vulnerable · 1 platform

Vulnerable Software	Affected Versions
Microsoft Office 365	Before 16.111.26071215

Running on/with	Platform Versions
Apple Macos	All versions

Related CWEs

Out-of-bounds Read

The product reads data past the end, or before the beginning, of the intended buffer.

References (1)

https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-55054

Source: secure@microsoft.com

Vendor Advisory

Timeline

No history available yet.