CVE-2026-55040

Analyzed Analyzed - Analysis Complete

Authentication Bypass in Microsoft Office SharePoint

Publication date: 2026-07-14

Last updated on: 2026-07-15

Assigner: Microsoft Corporation

Description

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

CVSS Scores

EPSS Scores

Probability:
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Meta Information

Published

2026-07-14

Last Modified

2026-07-15

Generated

2026-08-04

AI Q&A

2026-07-15

EPSS Evaluated

2026-08-02

NVD

CVE-2026-55040

EUVD

EUVD-2026-44211

Affected Vendors & Products

Vendor	Product	Version / Range
microsoft	sharepoint_server	2019
microsoft	sharepoint_server	2016
microsoft	sharepoint_server	to 16.0.19725.20434 (exc)

Helpful Resources

Exploitability

CWE

KEV

CWE ID	Description
CWE-1390	The product uses an authentication mechanism to restrict access to specific users or identities, but the mechanism does not sufficiently prove that the claimed identity is correct.

Attack-Flow Graph

Executive Summary

This vulnerability involves weak authentication in Microsoft Office SharePoint that allows an unauthorized attacker to bypass a security feature over a network. It enables attackers to gain unauthorized access without proper authentication.

Impact Analysis

An attacker could exploit this to bypass authentication and gain unauthorized access to sensitive data or systems in SharePoint. This may lead to data breaches, unauthorized modifications, or further network infiltration.

Compliance Impact

This vulnerability could lead to unauthorized access to personal or sensitive data, violating GDPR and HIPAA requirements for data protection and access controls. Non-compliance may result in legal penalties and reputational damage.

Mitigation Strategies

Apply the latest security updates from Microsoft for Office SharePoint immediately to address the weak authentication issue.

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