# CVE-2026-121681: Microsoft Trace Data Helper heap-based buffer overflow

Source: https://junglewise.ai/threats/cve-2026-121681-heap-based-buffer-overflow-in-microsoft-trace-data-helper-allows  
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-2026-121681 · Severity: high · CVSS 7.8 · Published 2026-11-10

Microsoft Trace Data Helper is a Windows system component used for diagnostic tracing and performance monitoring. A heap-based buffer overflow vulnerability in this component allows an authenticated local attacker to execute arbitrary code with elevated system privileges, potentially compromising the entire computer.

Technologies: [Microsoft Trace Data Helper](https://junglewise.ai/threats/technologies/trace-data-helper). Vendors: [Microsoft](https://junglewise.ai/threats/vendors/microsoft).

## Quick answers

**Is CVE-2026-121681 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-121681 being exploited in the wild.

**How severe is CVE-2026-121681?** High severity, with a CVSS score of 7.8, published 10 November 2026.

**Which products and versions are affected?** Microsoft Trace Data Helper.

**Is there a fix for CVE-2026-121681?** 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-2026-121681 attacked?** It is attacked with local access, in an operating system.

**Am I affected by CVE-2026-121681?** Check whether you run Microsoft Trace Data Helper. 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 exists in Microsoft Trace Data Helper that can be triggered by an authorized local user with standard privileges. Exploitation requires local network access and prior authentication; successful exploitation results in privilege escalation and arbitrary code execution with system-level access.

## Affected products

- Microsoft Trace Data Helper

## Timeline

- 2026-11-10: disclosed

## References

- [https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-121681](https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-121681)

## Related threats

- [Microsoft Trace Data Helper use-after-free privilege escalation](https://junglewise.ai/threats/cve-2026-122172-use-after-free-in-microsoft-trace-data-helper-allows-an)
- [Microsoft Trace Data Helper information disclosure](https://junglewise.ai/threats/cve-2026-70260-exposure-of-sensitive-system-information-to-an-unauthorized)