# CVE-2026-65665: Microsoft Office SharePoint deserialization of untrusted data in network communication

Source: https://junglewise.ai/threats/cve-2026-65665-microsoft-office-sharepoint-deserialization-of-untrusted-data-in  
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-2026-65665 · Severity: high · CVSS 8.8 · Published 2026-08-11

Microsoft Office SharePoint is a collaborative document and content management platform used by organizations to store and share business files and information. This vulnerability allows an authenticated attacker to execute malicious code on servers running SharePoint by sending specially crafted network requests that exploit unsafe deserialization, potentially compromising data confidentiality and system availability.

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

## Quick answers

**Is CVE-2026-65665 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-65665 being exploited in the wild.

**How severe is CVE-2026-65665?** High severity, with a CVSS score of 8.8, published 11 August 2026.

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

**Is there a fix for CVE-2026-65665?** 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-2026-65665 attacked?** It is attacked over the network.

**Am I affected by CVE-2026-65665?** 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

The vulnerability is a deserialization flaw in Microsoft Office SharePoint that permits remote code execution when processing untrusted serialized objects. An authorized attacker can craft malicious serialized data and transmit it over the network to trigger arbitrary code execution on affected SharePoint servers. The attack requires authentication and network connectivity to the vulnerable SharePoint instance. Exploitation allows an attacker to run commands with the privileges of the SharePoint application process. Microsoft has issued security patches to address this vulnerability.

## Affected products

- Microsoft Office SharePoint

## Timeline

- 2026-08-11: disclosed

## References

- [https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-65665](https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-65665)

## 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)