CVE-2026-55023 Microsoft CVE debrief

Who should care

Users of Microsoft Office, particularly those using 365 Apps, Office 2016, Office 2019, Office 2021, Office 2024, and SharePoint Server, should be aware of this vulnerability and take necessary actions to protect their systems.

Technical summary

The vulnerability is an out-of-bounds read issue in Microsoft Office, specifically affecting 365 Apps, Office 2016, Office 2019, Office 2021, Office 2024, and SharePoint Server. This could allow an unauthorized attacker to disclose information locally. The CVSS score is 5.5, and the severity is MEDIUM. Users should apply patches provided by Microsoft and monitor for potential exploitation attempts. The CVE record was published on 2026-07-14T18:18:12.913Z. Evidence from the CVE record and NVD details indicates that Microsoft has provided a patch and vendor advisory for this issue. Defenders should verify patch deployment and monitor for potential exploitation attempts within their environments.

Defensive priority

Medium priority should be given to patching this vulnerability, as it could allow local information disclosure.

Recommended defensive actions

• Apply patches provided by Microsoft
• Inventory and update affected Microsoft Office installations
• Monitor for potential exploitation attempts
• Review compensating controls for exposed systems while remediation is scheduled and verified
• Check relevant monitoring, detection, and logs for exposed assets that need extra review

Evidence notes

The CVE record and NVD details provide information on the vulnerability. Microsoft has provided a patch and vendor advisory for this issue. Evidence is limited to CVE and NVD details. Defenders should verify patch deployment and monitor for potential exploitation attempts within their environments.

Official resources