CVE-2026-21261HighCVSS 5.5
Microsoft Excel Information Disclosure Vulnerability
🔗 CVE IDs covered (1)
📋 Description
Out-of-bounds read in Microsoft Office Excel allows an unauthorized attacker to disclose information locally.
🎯 Affected products13
- Microsoft 365 Apps for Enterprise for 32-bit Systems
- Microsoft 365 Apps for Enterprise for 64-bit Systems
- Microsoft Excel 2016 (32-bit edition)
- Microsoft Excel 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
- Microsoft Office LTSC for Mac 2021
- Microsoft Office LTSC for Mac 2024
- Office Online Server
✅ Remediation
KB5002835 (Security Update) — fixed build 16.0.10417.20097 KBClick to Run (Security Update) — fixed build https://aka.ms/OfficeSecurityReleases KBRelease Notes (Security Update) — fixed build 16.106.26020821 KB5002837 (Security Update) — fixed build 16.0.5539.1002
🔗 References (7)
- advisoryhttps://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-21261
- patchhttps://www.microsoft.com/en-us/download/details.aspx?id=108551
- referencehttps://support.microsoft.com/help/5002835
- referencehttps://docs.microsoft.com/en-us/officeupdates/microsoft365-apps-security-updates
- patchhttps://go.microsoft.com/fwlink/p/?linkid=831049
- patchhttps://www.microsoft.com/en-us/download/details.aspx?id=108555
- referencehttps://support.microsoft.com/help/5002837