Improper Validation of Specified Type of Input in Microsoft products - CVE-2026-55124
Published: July 17, 2026
Vulnerability identifier: #VU138215
CSH Severity: Medium
CVSS v4: 6.7 [CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-55124
CWE-ID: CWE-1287
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to disclose sensitive information.
The vulnerability exists due to improper validation of specified type of input in Microsoft Word when parsing a crafted Office file. A remote attacker can send a specially crafted file to a user and convince them to open it to disclose sensitive information.
User interaction is required to open a crafted file, and the Preview Pane is not an attack vector.
Affected software
Microsoft Office for macOS
Microsoft Word
Microsoft SharePoint Server
Microsoft Word
Microsoft SharePoint Server
How to mitigate CVE-2026-55124
Install security update from vendor's website.
Microsoft Office for macOS - update to 16.111.26071215
Microsoft Word - update to 16.0.5561.1000
Microsoft SharePoint Server - addressed in versions 16.0.5561.1001, 16.0.10417.20175, 16.0.19725.20434
Microsoft Word - update to 16.0.5561.1000
Microsoft SharePoint Server - addressed in versions 16.0.5561.1001, 16.0.10417.20175, 16.0.19725.20434