CVE-2026-45659
Microsoft SharePoint Server Deserialization of Untrusted Data Vulnerability
Exploited in the wild
This vulnerability is on the CISA Known Exploited Vulnerabilities list, added 2026-07-01. Federal due date: 2026-07-04.
Apply mitigations in accordance with vendor instructions, ensuring compliance with CISA’s BOD 26-04 Prioritizing Security Updates Based on Risk (see URL in Notes) guidance and CISA’s “Forensics Triage Requirements” (see URL in Notes). Follow applicable BOD 26-04 guidance for cloud services or discontinue use of the product if mitigations are unavailable. Stakeholders are responsible for evaluating each asset's internet exposure and ensuring adherence to BOD 26-04 patching guidelines.
Impact
Microsoft SharePoint Server contains a deserialization of untrusted data vulnerability which allows an authorized attacker to execute code over a network.
Affected products
| Vendor | Product | Affected versions |
|---|---|---|
| Microsoft | Sharepoint Server | before 16.0.19725.20280 Versions 2016, 2019 |