CVE-2026-55124: Microsoft 365 Apps

Medium severity, CVSS 5.5. EPSS: 0.6% chance of exploitation in the next 30 days.

Improper validation of specified type of input in Microsoft Office Word allows an unauthorized attacker to disclose information locally.

Affected products

  • Microsoft 365 Apps: affected versions not specified
  • Microsoft Microsoft 365: affected versions not specified
  • Microsoft Office 2019: affected versions not specified
  • Microsoft Office 2021: affected versions not specified
  • Microsoft Office 2024: affected versions not specified
  • Microsoft Office Online Server: before 16.0.10417.20175 (fixed in 16.0.10417.20175)
  • Microsoft SharePoint Server: before 16.0.19725.20434 (fixed in 16.0.19725.20434); version 2016 only; version 2019 only
  • Microsoft Word: version 2016 only

Published 2026-07-14. Last modified 2026-07-16.