CVE intelligence

CVE-2026-78518

Vulnerability intelligence

Published Sep 8, 2026Sources checked Oct 28, 2026

8.8HIGHCVSS out of 10

What this means

Review the available evidence

CVE-2026-78518 and is rated High severity with a CVSS score of 8.8. 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 17, 2026

Vendor remediation details

Release Notes Install KB5002914. Install KB5002904.

Vendor-listed releases

16.0.10417.20207
16.0.20326.20138
16.113.26091433
16.0.14334.20906
16.0.17932.20976
16.0.5569.1003

CISA KEVNot listedBased on the latest collected catalog

EPSS0.9%Estimated 30-day exploitation probability

Ransomware useNot markedCISA KEV ransomware field

Threat actors0Source-linked actor relationships

Overview

What is CVE-2026-78518?

Out-of-bounds read in Microsoft Office Excel allows an unauthorized attacker to execute code over a network.

Source: NVD