# CVE-2026-69371: Microsoft Windows Overlay Filter heap buffer overflow

Source: https://junglewise.ai/threats/cve-2026-69371-microsoft-windows-overlay-filter-heap-buffer-overflow  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-09-08. Updated: 2026-09-26  
License: CC BY 4.0 with a link back

CVE-2026-69371 · Severity: high · CVSS 8 · Published 2026-09-08

Windows Overlay Filter is a system component that manages visual layering in the Windows operating system. A heap-based buffer overflow in this component allows an authorized attacker to elevate their privileges to a higher security level, potentially gaining administrative access to the system.

Technologies: [Microsoft Windows Overlay Filter](https://junglewise.ai/threats/technologies/windows-overlay-filter). Vendors: [Microsoft](https://junglewise.ai/threats/vendors/microsoft).

## Quick answers

**Is CVE-2026-69371 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-69371 being exploited in the wild.

**How severe is CVE-2026-69371?** High severity, with a CVSS score of 8, published 8 September 2026.

**Which products and versions are affected?** Microsoft Windows Overlay Filter.

**Is there a fix for CVE-2026-69371?** 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-2026-69371 attacked?** It is attacked over the network.

**Am I affected by CVE-2026-69371?** 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

This vulnerability is a heap-based buffer overflow in Microsoft's Windows Overlay Filter component. The flaw requires authentication and network-based access to exploit, allowing an authorized attacker to overflow a heap buffer and achieve privilege escalation. By corrupting heap memory, an attacker can potentially overwrite critical data structures to gain elevated privileges beyond their current authorization level. Microsoft has issued a security update to address this vulnerability.

## Affected products

- Microsoft Windows Overlay Filter

## Timeline

- 2026-09-08: disclosed

## References

- [https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-69371](https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-69371)

## Related threats

- [Windows Overlay Filter race condition privilege escalation](https://junglewise.ai/threats/cve-2026-121670-concurrent-execution-using-shared-resource-with-improper)
- [Microsoft Windows Overlay Filter race condition privilege escalation](https://junglewise.ai/threats/cve-2026-112813-concurrent-execution-using-shared-resource-with-improper)
- [Windows Overlay Filter integer overflow privilege escalation](https://junglewise.ai/threats/cve-2026-112760-integer-overflow-or-wraparound-in-windows-overlay-filter-allows)
- [Microsoft Windows Overlay Filter information disclosure](https://junglewise.ai/threats/cve-2026-108409-exposure-of-sensitive-system-information-to-an-unauthorized)
- [Windows Overlay Filter missing authorization](https://junglewise.ai/threats/cve-2026-96315-missing-authorization-in-windows-overlay-filter-allows-an)