CVE-2026-21511
No fix known EPSS 4%CVSS 7.5
Deserialization of untrusted data in Microsoft Office Outlook allows an unauthorized attacker to perform spoofing over a network.
Products: Microsoft 365 Apps for Enterprise, Microsoft Office 2019, Microsoft Office LTSC 2021, Microsoft Office LTSC 2024, Microsoft Office LTSC for Mac 2021, Microsoft Office LTSC for Mac 2024, Microsoft SharePoint Enterprise Server 2016, Microsoft SharePoint Server 2019, Microsoft SharePoint Server Subscription Edition, Microsoft Word 2016