Vulnerability Intelligence Report
Microsoft SharePoint Remote Code Execution Vulnerability
CVE-2026-45659
Deserialization of untrusted data in Microsoft Office SharePoint allows an authorized attacker to execute code over a network.
CISA KEV
SSVC: Active Exploitation
Deserialization
CVSS Base Score
8.8
HIGH
Exploitability:2.9
Impact Score:5.9
EPSS Probability:9.12%
Executive Threat Verdict
Evaluating...
Evaluating Threat Landscape...
Assessing known weaponization, exploitation telemetry, and federal advisories.
Attack Surface
—
Authentication
—
Weaponization
—
SSVC Action
—
Weaknesses (CWE)
CWE-502 ↗CWE-502: Deserialization of Untrusted Data
Affected Products & Versions
| Vendor | Product | Affected Versions |
|---|---|---|
| Microsoft | Microsoft SharePoint Enterprise Server 2016 | 16.0.0 < 16.0.5552.1002 (affected) |
| Microsoft | Microsoft SharePoint Server 2019 | 16.0.0 < 16.0.10417.20128 (affected) |
| Microsoft | Microsoft SharePoint Server Subscription Edition | 16.0.0 < 16.0.19725.20280 (affected) |
References & Technical Advisories
No reference links found.
Threat Intelligence Signals
CISA KEV
ACTIVE IN CATALOG
EPSS Score
9.120%
GitHub Advisory
Vulnerability Class
Deserialization
Identity & Timeline
| Status | PUBLISHED |
| Assigning Authority | Microsoft Corporation · Vendor · USA |
| Reserved | 2026-05-12T20:33:35 |
| Published | 2026-05-22T22:04:33 |
| Patch Date | 2026-05-21 |
| Last Updated | 2026-08-11T03:55:31 |
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