CVE intelligence

CVE-2026-55053

Vulnerability intelligence

Published Jul 14, 2026Sources checked Nov 12, 2026

7.8HIGHCVSS out of 10

What this means

Review the available evidence

CVE-2026-55053 and is rated High severity with a CVSS score of 7.8. It is not in the current CISA KEV record we collected. That does not prove exploitation has not occurred.

What to do next

Remediation and response

Microsoft Security Response Center guidance

Vendor revision: Sep 15, 2026

Vendor remediation details

Release Notes Click to Run Install KB5002884. Install KB5002886.

Vendor-listed releases

16.111.26071215
16.0.10417.20175
https://aka.ms/OfficeSecurityReleases
16.0.5561.1001

CISA KEVNot listedBased on the latest collected catalog

EPSS0.5%Estimated 30-day exploitation probability

Ransomware useNot markedCISA KEV ransomware field

Threat actors0Source-linked actor relationships

Overview

What is CVE-2026-55053?

Heap-based buffer overflow in Microsoft Office Excel allows an unauthorized attacker to execute code locally.

Source: NVD