CVE intelligence

CVE-2026-78457

Vulnerability intelligence

Published Sep 8, 2026Sources checked Oct 27, 2026

7.0HIGHCVSS out of 10

What this means

Review the available evidence

CVE-2026-78457 and is rated High severity with a CVSS score of 7.0. 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 8, 2026

Vendor remediation details

Install KB5122882. Install KB5122871. Install KB5124008. Install KB5124012.

Vendor-listed releases

10.0.20348.5622
10.0.26100.33438
10.0.26200.9445
10.0.26100.9445
10.0.28000.2954

CISA KEVNot listedBased on the latest collected catalog

EPSS0.3%Estimated 30-day exploitation probability

Ransomware useNot markedCISA KEV ransomware field

Threat actors0Source-linked actor relationships

Overview

What is CVE-2026-78457?

Use after free in Windows Security App allows an authorized attacker to elevate privileges locally.

Source: NVD