CVE-2026-54988 Microsoft CVE debrief

Who should care

Users of Microsoft Office Excel, particularly those with local access, should be aware of this vulnerability as it allows for information disclosure. This vulnerability requires local access and user interaction to exploit, making it a concern for those who use Excel in local environments.

Technical summary

CVE-2026-54988 is an out-of-bounds read vulnerability in Microsoft Office Excel. This vulnerability allows an unauthorized attacker to disclose information locally. The vulnerability has a CVSS score of 6.1 and a severity of MEDIUM. It requires local access and user interaction to exploit. Users of Microsoft Office Excel, particularly those with local access, should be aware of this vulnerability as it allows for information disclosure.

Defensive priority

Medium priority should be given to patching this vulnerability, especially in environments where local access to Excel is common.

Recommended defensive actions

• Apply the patch provided by Microsoft
• Ensure that only authorized personnel have local access to Microsoft Office Excel
• Monitor for any suspicious local activity on systems with Excel installed
• 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 indicate an out-of-bounds read vulnerability in Microsoft Office Excel. The CVSS vector is CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:H, indicating a medium severity vulnerability that allows for information disclosure. The vulnerability has a CVSS score of 6.1 and a severity of MEDIUM. It requires local access and user interaction to exploit.

Official resources