CVE-2026-21259 HIGH

CVE-2026-21259: Microsoft Excel Elevation of Privilege Vulnerability

Vendor Microsoft
Product Microsoft 365 Apps for Enterprise
Weakness CWE-122
Published February 10, 2026
Last update May 11, 2026
View on NVD All CVEs

CVSS base score

7.8/10
Attack vector Local
Attack complexity Low
Privileges required None
User interaction Required
Confidentiality High
Integrity High

CVSS vector

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

What the vulnerability does

01Description

Heap-based buffer overflow in Microsoft Office Excel allows an unauthorized attacker to elevate privileges locally.

Key dates

02Disclosure timeline

February 10, 2026 CVE published
May 11, 2026 Record updated