CVE-2026-56164 in SharePoint Server
Summary
by MITRE • 07/14/2026
Missing authentication for critical function in Microsoft Office SharePoint allows an unauthorized attacker to elevate privileges over a network.
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Analysis
by VulDB Data Team • 07/14/2026
This vulnerability represents a critical authentication flaw in Microsoft Office SharePoint that enables unauthorized attackers to escalate their privileges within the network environment. The issue stems from insufficient validation mechanisms during critical function execution, allowing malicious actors to bypass standard authentication protocols and gain elevated access rights. Such vulnerabilities fall under the CWE-863 category of "Incorrect Authorization" which specifically addresses scenarios where authorization checks are improperly implemented or omitted entirely.
The technical implementation of this flaw permits attackers to exploit weak authentication controls within SharePoint's privilege escalation mechanisms. When users attempt to perform critical administrative functions, the system fails to properly verify their credentials or authorization levels before granting access to elevated capabilities. This creates a pathway for attackers to execute privileged operations without proper authentication, potentially leading to complete system compromise. The vulnerability may manifest through various attack vectors including web-based exploitation, API manipulation, or direct network access to SharePoint services.
The operational impact of this vulnerability extends far beyond simple unauthorized access, as it provides attackers with the ability to manipulate core SharePoint functionalities and potentially escalate their privileges to administrative levels. Once exploited, attackers can modify user permissions, access sensitive documents, alter system configurations, and potentially use the compromised SharePoint instance as a foothold for lateral movement throughout the network infrastructure. This type of vulnerability directly aligns with ATT&CK technique T1078 which covers legitimate credentials usage and privilege escalation tactics.
Organizations implementing SharePoint solutions face significant risk exposure due to this authentication gap, particularly in environments where SharePoint serves as a central collaboration platform with extensive user access controls. The vulnerability becomes especially dangerous when combined with other network reconnaissance efforts, as attackers can leverage the compromised SharePoint instance to pivot into adjacent systems and expand their operational scope. Security teams must consider both immediate patching strategies and broader network segmentation approaches to limit potential exploitation impact.
Recommended mitigations include implementing proper authentication controls for all critical functions within SharePoint environments, ensuring that each administrative operation requires valid credential verification before execution. Organizations should also deploy robust monitoring solutions to detect anomalous privilege escalation attempts and establish strict access controls based on the principle of least privilege. Additionally, regular security assessments and penetration testing should be conducted to identify similar authentication gaps in SharePoint configurations. The vulnerability demonstrates the critical importance of maintaining proper authorization mechanisms in enterprise collaboration platforms, as failures in this area can result in severe security breaches with widespread operational consequences.