Unrated severityCISA KEVNVD Advisory· Published Jan 26, 2026· Updated Apr 1, 2026
Microsoft Office Security Feature Bypass Vulnerability
CVE-2026-21509
Description
Reliance on untrusted inputs in a security decision in Microsoft Office allows an unauthorized attacker to bypass a security feature locally.
Affected products
5- Microsoft/Microsoft 365 Apps for Enterprisev5Range: 16.0.1
- Microsoft/Microsoft Office 2016v5Range: 16.0.0
- Microsoft/Microsoft Office 2019v5Range: 19.0.0
- Microsoft/Microsoft Office LTSC 2021v5Range: 16.0.1
- Microsoft/Microsoft Office LTSC 2024v5Range: 16.0.0
Patches
0No patches discovered yet.
Vulnerability mechanics
AI mechanics synthesis has not run for this CVE yet.
References
1- msrc.microsoft.com/update-guide/vulnerability/CVE-2026-21509mitrevendor-advisorypatch
News mentions
1- Exploits and vulnerabilities in Q1 2026Securelist · May 7, 2026