CVE-2026-42979: Windows Push Notifications Elevation of Privilege Vulnerability

Synopsis

A race condition in the Windows Push Notifications subsystem allows a low-privileged local attacker to escalate to higher privileges on affected Windows 10 and Windows 11 systems. The flaw is reached locally and requires no interaction from other users, but the attacker must win a timing-dependent race over a shared resource. Successful exploitation gives the attacker full control over confidentiality, integrity, and availability of the system. Patched-image rebuilds at the fixed versions are available on HarborGuard for environments running affected Windows base images.

HarborGuard Coverage

Exploit Conditions

• Network reachabilityNot required

  The attacker needs an existing shell or process on the host; no network path to the service is required.

• AuthenticationRequired

  Any low-privilege local account is sufficient; the attacker does not need administrative credentials.

• Victim interactionNot required

  No other user needs to open a file, click a link, or take any action for the exploit to proceed.

• Attack complexityDetail

  Exploitation depends on winning a timing-sensitive race condition over a shared resource, making reliable triggering conditional on environmental factors and retry attempts.

Blast Radius

• A successful attacker gains elevated privileges and reads sensitive data accessible to higher-privileged processes, including credentials and session material stored by the OS.
• The attacker can write to protected system resources, modify configuration, or install persistent payloads that survive reboots.
• The attacker can crash or destabilize system services, causing denial of service for users on the affected host.