CVE-2026-55057 Microsoft CVE debrief

Who should care

System administrators and users of Microsoft Office should be aware of this vulnerability and take steps to mitigate it. The vulnerability can be mitigated by applying the patch released by Microsoft, ensuring that Microsoft Office is up to date, and monitoring for suspicious activity.

Technical summary

The vulnerability is caused by an integer overflow or wraparound in Microsoft Office. This can allow an attacker to disclose information locally. The vulnerability has a CVSS score of 5.5 and a severity of MEDIUM. The affected product is Microsoft Office, and the vulnerability can be mitigated by applying the patch released by Microsoft.

Defensive priority

Medium priority

Recommended defensive actions

• Apply the patch released by Microsoft
• Ensure that Microsoft Office is up to date
• Monitor for suspicious activity
• 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 for CVE-2026-55057 was published on 2026-07-14T18:18:17.953Z and was last modified on 2026-07-16T14:40:40.007Z. The NVD entry is currently Analyzed. The vulnerability is an integer overflow or wraparound in Microsoft Office, which allows an unauthorized attacker to disclose information locally. The source details are limited, and defenders should verify the affected scope and vendor guidance.

Official resources