Vulnerability Intelligence Report
Microsoft SharePoint Server Security Feature Bypass Vulnerability
CVE-2026-55040
Weak authentication in Microsoft Office SharePoint allows an unauthorized attacker to bypass a security feature over a network.
CISA KEV
Nuclei Template
SSVC: Active Exploitation
Automatable
CVSS Base Score
9.1
CRITICAL
Exploitability:3.9
Impact Score:5.2
EPSS Probability:50.59%
Executive Threat Verdict
Evaluating...
Evaluating Threat Landscape...
Assessing known weaponization, exploitation telemetry, and federal advisories.
Attack Surface
—
Authentication
—
Weaponization
—
SSVC Action
—
Weaknesses (CWE)
CWE-1390 ↗CWE-1390: Weak Authentication
Affected Products & Versions
| Vendor | Product | Affected Versions |
|---|---|---|
| Microsoft | Microsoft SharePoint Enterprise Server 2016 | 16.0.0 < 16.0.5561.1001 (affected) |
| Microsoft | Microsoft SharePoint Server 2019 | 16.0.0 < 16.0.10417.20175 (affected) |
| Microsoft | Microsoft SharePoint Server Subscription Edition | 16.0.0 < 16.0.19725.20434 (affected) |
References & Technical Advisories
No reference links found.
Threat Intelligence Signals
CISA KEV
ACTIVE IN CATALOG
Nuclei Template
SCANNER AVAILABLE
EPSS Score
50.585%
GitHub Advisory
Identity & Timeline
| Status | PUBLISHED |
| Assigning Authority | Microsoft Corporation · Vendor · USA |
| Reserved | 2026-06-16T14:13:49 |
| Published | 2026-07-14T17:09:00 |
| Patch Date | 2026-07-14 |
| Last Updated | 2026-09-17T22:32:59 |
Community Chatter & Buzz