CVE-2026-121670: Windows Overlay Filter race condition privilege escalation

CVE-2026-121670 · Severity: high · CVSS 7 · Published 2026-11-10

Windows Overlay Filter contains a race condition vulnerability that allows an authorized local attacker to escalate their privileges on the system. An attacker with limited user account access could potentially gain administrative rights, allowing them to install malware, modify system settings, or access sensitive data.

Technologies: Microsoft Windows Overlay Filter. Vendors: Microsoft.

Quick answers

Is CVE-2026-121670 exploited in the wild?
No. Junglewise Threat Intelligence has no report of CVE-2026-121670 being exploited in the wild.
How severe is CVE-2026-121670?
High severity, with a CVSS score of 7, published 10 November 2026.
Which products and versions are affected?
Microsoft Windows Overlay Filter.
Is there a fix for CVE-2026-121670?
No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.
How is CVE-2026-121670 attacked?
It is attacked with local access, in an operating system.
Am I affected by CVE-2026-121670?
Check whether you run Microsoft Windows Overlay Filter. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

Technical details

A race condition exists in the Windows Overlay Filter component due to improper synchronization when accessing shared resources. An authorized local attacker can exploit this timing vulnerability to escalate privileges. A fix is expected to be available from Microsoft.

Affected products

  • Microsoft Windows Overlay Filter

Timeline

  • 2026-11-10: disclosed

References

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