Out-of-bounds read in Microsoft products - CVE-2026-26109
Published: March 11, 2026
Vulnerability identifier: #VU123796
CSH Severity: High
CVSS v4.0: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Amber
CVE-ID: CVE-2026-26109
CWE-ID: CWE-125
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vendor: Microsoft
Affected software:
Microsoft Office
Microsoft 365 Apps for Enterprise
Microsoft Excel
Microsoft Office LTSC
Office Online Server
Microsoft Office
Microsoft 365 Apps for Enterprise
Microsoft Excel
Microsoft Office LTSC
Office Online Server
Detailed vulnerability description
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 trigger an out-of-bounds read error and read contents of memory on the system, leading to arbitrary code execution.
How to mitigate CVE-2026-26109
Install updates from vendor's website.