CVE-2026-21511

Summary

Deserialization of untrusted data in Microsoft Office Outlook allows an unauthorized attacker to perform spoofing over a network.

Affected Software

VendorProductVersion RangeStatus
MicrosoftMicrosoft 365 Apps for Enterprise16.0.1 < https://aka.ms/OfficeSecurityReleasesaffected
MicrosoftMicrosoft Office 201919.0.0 < https://aka.ms/OfficeSecurityReleasesaffected
MicrosoftMicrosoft Office LTSC 202116.0.1 < https://aka.ms/OfficeSecurityReleasesaffected
MicrosoftMicrosoft Office LTSC 202416.0.0 < https://aka.ms/OfficeSecurityReleasesaffected
MicrosoftMicrosoft Office LTSC for Mac 202116.0.1 < 16.106.26020821affected
MicrosoftMicrosoft Office LTSC for Mac 202416.0.0 < 16.106.26020821affected
MicrosoftMicrosoft SharePoint Enterprise Server 201616.0.0 < 16.0.5539.1002affected
MicrosoftMicrosoft SharePoint Server 201916.0.0 < 16.0.10417.20097affected
MicrosoftMicrosoft SharePoint Server Subscription Edition16.0.0 < 16.0.19127.20518affected
MicrosoftMicrosoft Word 201616.0.1 < 16.0.5539.1002affected

Weaknesses

  • CWE-502: CWE-502: Deserialization of Untrusted Data

ADP Enrichment

CISA ADP Vulnrichment

  • SSVC:
  • Exploitation: none
    • Automatable: yes
    • Technical Impact: partial

References