HIGHCVE-2026-21259Published Modified CNA microsoft
CVE-2026-21259: Microsoft Excel Elevation of Privilege Vulnerability
Heap-based buffer overflow in Microsoft Office Excel allows an unauthorized attacker to elevate privileges locally.
Metrics
- CVSS v3.1
- 7.8
- Severity
- HIGH
- Fixed in
- 16.0.5539.1002
- Affected Products
- 6
Fix available
16.0.5539.100216.0.10417.20097https://aka.ms/OfficeSecurityReleases
Patch commits
Affected packages
- Microsoft / Microsoft 365 Apps for Enterprise< https://aka.ms/OfficeSecurityReleases (from 16.0.1)
- Microsoft / Microsoft Excel 2016< 16.0.5539.1002 (from 16.0.0.0)
- Microsoft / Microsoft Office 2019< https://aka.ms/OfficeSecurityReleases (from 19.0.0)
- Microsoft / Microsoft Office LTSC 2021< https://aka.ms/OfficeSecurityReleases (from 16.0.1)
- Microsoft / Microsoft Office LTSC 2024< https://aka.ms/OfficeSecurityReleases (from 16.0.0)
- Microsoft / Office Online Server< 16.0.10417.20097 (from 16.0.0.0)
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