CVE-2026-21259

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CVSS 3.1

7.8 high

EPSS

<1%p44

Published

Feb 10, 2026 (Feb 10, 2026)

Modified

Jun 17, 2026

Description

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

Vendors: microsoft
Products: 365 apps, excel, office, office long term servicing channel, office online server
Weakness: CWE-122, CWE-787
Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

NVD CVE.org GitHub PoCs EPSS (0.5%)

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