CVE-2026-21259

HIGH EPSS 40.4%
Published Feb 10, 20264mo ago · Modified Jun 17, 20261w ago
7.8 CVSS 3.1
High
Find Similar
Published Feb 10, 2026 4mo ago
Last Modified Jun 17, 2026 1w ago

Description

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

CVSS Details

Base Score
7.8
Exploitability
1.8
Impact
5.9
Vector string
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
Attack Vector Local
Attack Complexity Low
Privileges Required None
User Interaction Required
Scope Unchanged
Confidentiality High
Integrity High
Availability High

Threat Intelligence

EPSS Exploit Probability
40.4% percentile
Exploit & Patch Status
No Known Exploit
No Patch Available

Weaknesses 2

CWE-122
CWE-787 Out-of-bounds Write Memory Safety

Affected Products 11

VendorProductVersionRange
microsoft365_apps*any
microsoft365_apps*any
microsoftexcel2016any
microsoftexcel2016any
microsoftoffice2019any
microsoftoffice2019any
microsoftoffice_long_term_servicing_channel2021any
microsoftoffice_long_term_servicing_channel2021any
microsoftoffice_long_term_servicing_channel2024any
microsoftoffice_long_term_servicing_channel2024any
microsoftoffice_online_server* <16.0.10417.20097

References 1

  • msrc.microsoft.com https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-21259
    Vendor Advisory

Remediation

No remediation data recorded yet

Check vendor advisories and the NVD entry for patch availability.