CVE-2026-42978 Windows Push Notifications Elevation of Privilege Vulnerability

High 7.8 Published Updated

A race condition in Windows Push Notifications allows an authorized local attacker to elevate privileges.

Exploited in the wild
Not known
Login needed
Any signed-in user
Attackable
Local or same network only
Victim action needed
Not needed
Fix
None listed

What is CVE-2026-42978?

CVE-2026-42978 is a high-severity vulnerability in Microsoft Windows 10 1809, published on 9 Jun 2026. It can only be exploited from the same machine or local network, with no action from the victim.

Official description

Concurrent execution using shared resource with improper synchronization ('race condition') in Windows Push Notifications allows an authorized attacker to elevate privileges locally.

Weakness: CWE-416, CWE-362

Which versions are affected by CVE-2026-42978?

It affects 10 products.

Products include Microsoft Windows 10 1809, Microsoft Windows 10 21h2, Microsoft Windows 10 22h2, Microsoft Windows 11 23h2, Microsoft Windows 11 24h2, Microsoft Windows 11 25h2 and 4 more.

How do I fix CVE-2026-42978?

No fix has been published for CVE-2026-42978 yet. Limit exposure of the affected software until one is available.

Is CVE-2026-42978 being exploited?

There is no known exploitation of CVE-2026-42978 in the wild and no public exploit code.

Public exploit code: 5 proofs of concept on GitHub.

All Microsoft Windows 10 1809 vulnerabilities

Sources

Also known as GHSA-mjxj-356g-98wq.

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