CVE intelligence

CVE-2026-40378

Vulnerability intelligence

Published Jul 14, 2026Sources checked Sep 12, 2026

7.5HIGHCVSS out of 10

What this means

Review the available evidence

CVE-2026-40378 and is rated High severity with a CVSS score of 7.5. It is not in the current CISA KEV record we collected. That does not prove exploitation has not occurred.

CISA KEVNot listedBased on the latest collected catalog

EPSS1.2%Estimated 30-day exploitation probability

Ransomware useNot markedCISA KEV ransomware field

Threat actors0Source-linked actor relationships

Overview

What is CVE-2026-40378?

Memory allocation with excessive size value in Windows Local Security Authority Subsystem Service (LSASS) allows an unauthorized attacker to deny service over a network.