# CVE-2026-70321: Deserialization of untrusted data in Microsoft Office SharePoint allows an authorized attacker to execute code over a network.

Source: https://junglewise.ai/threats/cve-2026-70321-deserialization-of-untrusted-data-in-microsoft-office-sharepoint  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-08-11  
License: CC BY 4.0 with a link back

CVE-2026-70321 · Severity: high · CVSS 8.8 · Published 2026-08-11

Deserialization of untrusted data in Microsoft Office SharePoint allows an authorized attacker to execute code over a network.

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

## Quick answers

**Is CVE-2026-70321 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-70321 being exploited in the wild.

**How severe is CVE-2026-70321?** High severity, with a CVSS score of 8.8, published 11 August 2026.

**Which products and versions are affected?** Microsoft SharePoint Server. The advisory does not name versions.

**Is there a fix for CVE-2026-70321?** 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.

**Am I affected by CVE-2026-70321?** Check whether you run Microsoft SharePoint Server. 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.

## Affected products

- Microsoft SharePoint Server

## Related threats

- [Microsoft Office SharePoint cross-site scripting](https://junglewise.ai/threats/cve-2026-97783-improper-neutralization-of-input-during-web-page-generation-cross)
- [Microsoft Office SharePoint observable discrepancy tampering](https://junglewise.ai/threats/cve-2026-97782-observable-discrepancy-in-microsoft-office-sharepoint-allows-an)
- [Microsoft Office SharePoint privilege elevation](https://junglewise.ai/threats/cve-2026-96044-no-cwe-for-this-issue-in-microsoft-office-sharepoint-allows-an)
- [Microsoft Office SharePoint path traversal code execution](https://junglewise.ai/threats/cve-2026-69943-improper-limitation-of-a-pathname-to-a-restricted-directory-path)
- [Microsoft Office SharePoint incorrect authorization privilege escalation](https://junglewise.ai/threats/cve-2026-105720-incorrect-authorization-in-microsoft-office-sharepoint-allows-an)