# CVE-2026-105503: Microsoft Windows Management Instrumentation heap buffer overflow

Source: https://junglewise.ai/threats/cve-2026-105503-heap-based-buffer-overflow-in-windows-management-instrumentation  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-11-10. Updated: 2026-11-10  
License: CC BY 4.0 with a link back

CVE-2026-105503 · Severity: high · CVSS 7.8 · Published 2026-11-10

Windows Management Instrumentation (WMI) is a core Windows system component that manages hardware and software resources. A heap-based buffer overflow in WMI allows an authenticated local attacker to execute arbitrary code with elevated system privileges, potentially gaining complete control of the affected machine.

Technologies: [Microsoft Windows Management Instrumentation](https://junglewise.ai/threats/technologies/windows-management-instrumentation). Vendors: [Microsoft](https://junglewise.ai/threats/vendors/microsoft).

## Quick answers

**Is CVE-2026-105503 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-105503 being exploited in the wild.

**How severe is CVE-2026-105503?** High severity, with a CVSS score of 7.8, published 10 November 2026.

**Which products and versions are affected?** Microsoft Windows Management Instrumentation.

**Is there a fix for CVE-2026-105503?** 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-2026-105503 attacked?** It is attacked with local access.

**Am I affected by CVE-2026-105503?** Check whether you run Microsoft Windows Management Instrumentation. 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 heap-based buffer overflow vulnerability exists in Windows Management Instrumentation that can be exploited by an authenticated local user to achieve privilege escalation. The vulnerability requires local access and authentication credentials; it cannot be exploited remotely. Successful exploitation results in code execution with SYSTEM privileges.

## Affected products

- Microsoft Windows Management Instrumentation

## Timeline

- 2026-11-10: disclosed

## References

- [https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-105503](https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-105503)

## Related threats

- [Windows Management Instrumentation out-of-bounds read](https://junglewise.ai/threats/cve-2026-112814-out-of-bounds-read-in-windows-management-instrumentation-allows)
- [Microsoft Windows Management Instrumentation out-of-bounds read](https://junglewise.ai/threats/cve-2026-85852-out-of-bounds-read-in-windows-management-instrumentation-allows)
- [Microsoft Windows Management Instrumentation use-after-free privilege escalation](https://junglewise.ai/threats/cve-2026-77905-microsoft-windows-management-instrumentation-use-after-free)
- [Microsoft Windows Management Instrumentation information disclosure](https://junglewise.ai/threats/cve-2026-69349-microsoft-windows-management-instrumentation-information)