# CVE-2026-109499: Microsoft Office SharePoint type confusion remote code execution

Source: https://junglewise.ai/threats/cve-2026-109499-access-of-resource-using-incompatible-type-type-confusion-in  
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-2026-109499 · Severity: high · CVSS 8.8 · Published 2026-11-10

Microsoft Office SharePoint, a platform for document management and team collaboration, contains a type confusion vulnerability that allows an authenticated attacker to execute arbitrary code remotely. An attacker with valid credentials could leverage this flaw to compromise SharePoint servers and gain unauthorized access to sensitive business data or launch further attacks within an organization's network.

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

## Quick answers

**Is CVE-2026-109499 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-109499 being exploited in the wild.

**How severe is CVE-2026-109499?** High severity, with a CVSS score of 8.8, published 10 November 2026.

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

**Is there a fix for CVE-2026-109499?** 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-2026-109499 attacked?** It is attacked over the network.

**Am I affected by CVE-2026-109499?** Check whether you run Microsoft Office SharePoint. 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 type confusion vulnerability in Microsoft Office SharePoint allows an authorized network attacker to achieve remote code execution. The vulnerability requires valid authentication credentials to exploit. The flaw enables an attacker to access or manipulate resources using incompatible types, leading to arbitrary code execution on the affected SharePoint server.

## Affected products

- Microsoft Office SharePoint

## Timeline

- 2026-11-10: disclosed

## References

- [https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-109499](https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-109499)

## Related threats

- [Microsoft Office SharePoint privilege escalation via missing authorization](https://junglewise.ai/threats/cve-2026-88176-missing-authorization-in-microsoft-office-sharepoint-allows-an)
- [Microsoft Office SharePoint XSS privilege escalation](https://junglewise.ai/threats/cve-2026-80095-improper-neutralization-of-input-during-web-page-generation-cross)
- [Microsoft Office SharePoint server-side request forgery](https://junglewise.ai/threats/cve-2026-124210-server-side-request-forgery-ssrf-in-microsoft-office-sharepoint)
- [Microsoft Office SharePoint privilege escalation via incorrect authorization](https://junglewise.ai/threats/cve-2026-123391-incorrect-authorization-in-microsoft-office-sharepoint-allows-an)
- [Microsoft Office SharePoint deserialization of untrusted data](https://junglewise.ai/threats/cve-2026-123390-deserialization-of-untrusted-data-in-microsoft-office-sharepoint)