# CVE-2026-68817: Microsoft Office Excel stack-based buffer overflow

Source: https://junglewise.ai/threats/cve-2026-68817-microsoft-office-excel-stack-based-buffer-overflow  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-08-11. Updated: 2026-09-25  
License: CC BY 4.0 with a link back

CVE-2026-68817 · Severity: high · CVSS 7.8 · Published 2026-08-11

Microsoft Office Excel contains a stack-based buffer overflow vulnerability that allows an attacker to execute arbitrary code locally on affected systems. An attacker with local access could exploit this flaw to gain control of the system and compromise sensitive data or business operations.

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

## Quick answers

**Is CVE-2026-68817 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-68817 being exploited in the wild.

**How severe is CVE-2026-68817?** High severity, with a CVSS score of 7.8, published 11 August 2026.

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

**Is there a fix for CVE-2026-68817?** 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-2026-68817 attacked?** It is attacked with local access.

**Am I affected by CVE-2026-68817?** Check whether you run Microsoft Office Excel. 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 stack-based buffer overflow vulnerability exists in Microsoft Office Excel due to insufficient input validation when processing specially crafted spreadsheet files. The vulnerability requires local access to the affected system and can be triggered by opening a malicious Excel file. Successful exploitation allows an attacker to execute arbitrary code with the privileges of the user running Excel. Microsoft has released security patches to remediate this issue.

## Affected products

- Microsoft Office Excel

## Timeline

- 2026-08-11: disclosed

## References

- [https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-68817](https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-68817)

## Related threats

- [Microsoft Office Excel unsafe deserialization in file parsing](https://junglewise.ai/threats/cve-2026-124229-deserialization-of-untrusted-data-in-microsoft-office-excel)
- [Microsoft Office Excel use-after-free remote code execution](https://junglewise.ai/threats/cve-2026-124187-use-after-free-in-microsoft-office-excel-allows-an-unauthorized)
- [Microsoft Office Excel buffer over-read information disclosure](https://junglewise.ai/threats/cve-2026-124183-buffer-over-read-in-microsoft-office-excel-allows-an)
- [Microsoft Office Excel out-of-bounds read information disclosure](https://junglewise.ai/threats/cve-2026-124179-out-of-bounds-read-in-microsoft-office-excel-allows-an)
- [Microsoft Office Excel out-of-bounds read](https://junglewise.ai/threats/cve-2026-124178-out-of-bounds-read-in-microsoft-office-excel-allows-an)