Numeric Truncation Error in Microsoft Word - CVE-2026-63525
Published: August 12, 2026
Vulnerability identifier: #VU141934
CSH Severity: High
CVSS v4: 8.4 [CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-63525
CWE-ID: CWE-197
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to execute arbitrary code.
The vulnerability exists due to numeric truncation error in Microsoft Office Word when parsing a crafted Office file. A remote attacker can send a specially crafted file and trick the victim into opening it to execute arbitrary code.
User interaction is required to open a crafted file, and the Preview Pane is not an attack vector.
Affected software
Microsoft Word
How to mitigate CVE-2026-63525
Install security update from vendor's website.
Microsoft Word - update to 16.0.5565.1000