CVE-2026-21509HighCVSS 7.8
Microsoft Office Security Feature Bypass Vulnerability
🔗 CVE IDs covered (1)
📋 Description
Reliance on untrusted inputs in a security decision in Microsoft Office allows an unauthorized attacker to bypass a security feature locally.
🎯 Affected products10
- Microsoft 365 Apps for Enterprise for 32-bit Systems
- Microsoft 365 Apps for Enterprise for 64-bit Systems
- Microsoft Office 2016 (32-bit edition)
- Microsoft Office 2016 (64-bit edition)
- Microsoft Office 2019 for 32-bit editions
- Microsoft Office 2019 for 64-bit editions
- Microsoft Office LTSC 2021 for 32-bit editions
- Microsoft Office LTSC 2021 for 64-bit editions
- Microsoft Office LTSC 2024 for 32-bit editions
- Microsoft Office LTSC 2024 for 64-bit editions
✅ Remediation
KBClick to Run (Security Update) — fixed build 16.0.10417.20095 KBClick to Run (Security Update) — fixed build https://aka.ms/OfficeSecurityReleases KB5002713 (Security Update) — fixed build 16.0.5539.1001
🔗 References (5)
- advisoryhttps://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-21509
- referencehttps://learn.microsoft.com/en-us/officeupdates/update-history-office-2019
- referencehttps://docs.microsoft.com/en-us/officeupdates/office365-proplus-security-updates
- patchhttps://www.microsoft.com/en-us/download/details.aspx?id=108535
- referencehttps://support.microsoft.com/help/5002713