# CVE-2026-122198: Microsoft Office heap-based buffer overflow

Source: https://junglewise.ai/threats/cve-2026-122198-heap-based-buffer-overflow-in-microsoft-office-allows-an  
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-2026-122198 · Severity: high · CVSS 8.8 · Published 2026-11-10

Microsoft Office is a productivity suite used by millions of organizations for document creation and editing. A heap-based buffer overflow vulnerability could allow an attacker to execute arbitrary code on affected systems over a network, leading to potential data theft, system compromise, or installation of malware without user action.

Technologies: [Microsoft Office](https://junglewise.ai/threats/technologies/office). Vendors: [Microsoft](https://junglewise.ai/threats/vendors/microsoft).

## Quick answers

**Is CVE-2026-122198 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-122198 being exploited in the wild.

**How severe is CVE-2026-122198?** High severity, with a CVSS score of 8.8, published 10 November 2026.

**Which products and versions are affected?** Microsoft Office.

**Is there a fix for CVE-2026-122198?** 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-2026-122198 attacked?** It is attacked over the network.

**Am I affected by CVE-2026-122198?** Check whether you run Microsoft Office. 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 Microsoft Office that permits remote code execution over the network. The vulnerability can be triggered without user authentication, making it accessible to network attackers. Successful exploitation results in arbitrary code execution with the privileges of the affected Office process.

## Affected products

- Microsoft Office

## Timeline

- 2026-11-10: disclosed

## References

- [https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-122198](https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-122198)

## Related threats

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- [Microsoft Office heap-based buffer overflow](https://junglewise.ai/threats/cve-2026-120003-heap-based-buffer-overflow-in-microsoft-office-allows-an)
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- [Microsoft Office buffer over-read information disclosure](https://junglewise.ai/threats/cve-2026-112731-buffer-over-read-in-microsoft-office-allows-an-unauthorized)