CVE-2026-21259

high Microsoft
CVSS v3 Base Score
7.8
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
EPSS Score
0.0%
Exploitation probability in 30 days
Top 94% most likely to be exploited
Attack Characteristics
Attack Vector
Local
Attack Complexity
Low
Privileges Required
None
User Interaction
Required
Confidentiality
High
Integrity
High
Availability
High
Published: February 10, 2026 (93 days ago)
Last Modified: March 13, 2026
Vendor: Microsoft
Source: MITRE

Description

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

CWE

CWE-122

Affected Products

Microsoft Microsoft 365 Apps for EnterpriseMicrosoft Microsoft Excel 2016Microsoft Microsoft Office 2019Microsoft Microsoft Office LTSC 2021Microsoft Microsoft Office LTSC 2024Microsoft Office Online Server

References

🔗 msrc.microsoft.com