CVE-2026-20949

Microsoft Excel Security Feature Bypass Vulnerability

State: Published
Severity: 7.8 High
Published: Jan 13, 2026
Updated: Jul 30, 2026
Reserved: Dec 4, 2025

Description

Improper access control in Microsoft Office Excel allows an unauthorized attacker to bypass a security feature locally.

Scores

CVSS	Score	Vector	Source
3.1	7.8 High	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	microsoft

Weaknesses

CWE-284 Improper Access Control

Affected Products

Product	Versions
Microsoft 365 Apps for EnterpriseMicrosoft	16.0.1 to before https://aka.ms/OfficeSecurityReleasesAffected
Microsoft Office LTSC 2021Microsoft	16.0.1 to before https://aka.ms/OfficeSecurityReleasesAffected
Microsoft Office LTSC 2024Microsoft	16.0.0 to before https://aka.ms/OfficeSecurityReleasesAffected
Microsoft Office LTSC for Mac 2021Microsoft	16.0.1 to before 16.105.26011018Affected
Microsoft Office LTSC for Mac 2024Microsoft	16.0.0 to before 16.105.26011018Affected

References

Microsoft Excel Security Feature Bypass Vulnerabilityvendor-advisorypatch

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