HIGH Actively exploited Used in ransomware CWE-502
CVE-2026-45659
Microsoft SharePoint Remote Code Execution Vulnerability
Microsoft·SharePoint Server
8.8/ 10
CVSS 3.1
High severity
80%
EPSS exploit odds
Chance of exploitation in the next 30 days
Higher than 99.6% of all CVEs
Listed
CISA KEV catalog
- Added
- Jul 1, 2026
- Fix due
- Jul 4, 2026
- Ransomware
- Known use
Timeline
- Published
- May 22, 2026
- Updated
- Aug 11, 2026
- First covered
- Jul 2, 2026
- Latest story
- 1 month ago
Summary
Deserialization of untrusted data in Microsoft Office SharePoint allows an authorized attacker to execute code over a network.
CWE-502Deserialization of Untrusted Data
Attack profile
Attack vectorNetwork
ComplexityLow
PrivilegesLow
User interactionNone
ScopeUnchanged
ConfidentialityHigh
IntegrityHigh
AvailabilityHigh
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:CCISA required action
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.
Affected products
- Microsoft SharePoint Enterprise Server 201616.0.0 to before 16.0.5552.1002
- Microsoft SharePoint Server 201916.0.0 to before 16.0.10417.20128
- Microsoft SharePoint Server Subscription Edition16.0.0 to before 16.0.19725.20280