CVE intelligence

CVE-2026-40357

Vulnerability intelligence

Published May 12, 2026Sources checked Nov 11, 2026

8.8HIGHCVSS out of 10

What this means

Review the available evidence

CVE-2026-40357 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: May 12, 2026

Install KB5002868. Install KB5002870. Install KB5002863.

Vendor-listed releases

16.0.5552.1002
16.0.10417.20128
16.0.19725.20280

CISA KEVNot listedBased on the latest collected catalog

EPSS1.7%Estimated 30-day exploitation probability

Ransomware useNot markedCISA KEV ransomware field

Threat actors0Source-linked actor relationships

Overview

What is CVE-2026-40357?

Deserialization of untrusted data in Microsoft Office SharePoint allows an authorized attacker to execute code over a network.

Source: NVD