CVE-2026-55040

CRITICAL

Microsoft SharePoint Server Security Feature Bypass Vulnerability

Title source: cna
STIX 2.1

Description

Weak authentication in Microsoft Office SharePoint allows an unauthorized attacker to bypass a security feature over a network.

References (1)

Core 1
Core References
Vendor Advisory vendor-advisory patch
Microsoft SharePoint Server Security Feature Bypass Vulnerability
https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-55040

Scores

CVSS v3 9.1
EPSS 0.0163
EPSS Percentile 73.8%
Attack Vector NETWORK
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N

CISA SSVC

Vulnrichment
Exploitation none
Automatable yes
Technical Impact total

Details

CWE
CWE-1390
Status published
Products (6)
Microsoft/Microsoft SharePoint Enterprise Server 2016 16.0.0 - 16.0.5561.1001
Microsoft/Microsoft SharePoint Server 2019 16.0.0 - 16.0.10417.20175
Microsoft/Microsoft SharePoint Server Subscription Edition 16.0.0 - 16.0.19725.20434
microsoft/sharepoint_server 2016
microsoft/sharepoint_server 2019
microsoft/sharepoint_server < 16.0.19725.20434
Published Jul 14, 2026
Tracked Since Jul 14, 2026