Out-of-bounds read in Microsoft products - CVE-2026-20946
Published: January 13, 2026
Vulnerability identifier: #VU121284
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-2026-20946
CWE-ID: CWE-125
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to gain access to potentially sensitive information.
The vulnerability exists due to a boundary condition in Microsoft Excel. A remote attacker can create a specially crafted file, trick the victim into opening it, trigger an out-of-bounds read error and read contents of memory on the system, leading to arbitrary code execution.
Affected software
Microsoft 365 Apps for Enterprise
Microsoft Excel
Microsoft Office
Microsoft Office LTSC
Microsoft Excel
Microsoft Office
Microsoft Office LTSC
How to mitigate CVE-2026-20946
Install updates from vendor's website.