CVE-2026-55052 in SharePoint Server
Summary
by MITRE • 07/14/2026
Missing authorization in Microsoft Office SharePoint allows an authorized attacker to elevate privileges over a network.
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Analysis
by VulDB Data Team • 07/15/2026
This vulnerability represents a critical authorization flaw in Microsoft Office SharePoint that enables authenticated attackers to escalate their privileges within the network environment. The issue stems from insufficient access controls that fail to properly validate user permissions when processing certain requests or operations. Attackers who have already gained initial access to the SharePoint environment can exploit this weakness to obtain elevated privileges, potentially allowing them to access sensitive data, modify content, or execute administrative functions that should be restricted to authorized personnel only.
The technical implementation of this vulnerability typically involves a failure in the authorization mechanism where the system does not adequately verify whether an authenticated user has the necessary permissions to perform specific actions. This can manifest through improper validation of user roles, session tokens, or access control lists during request processing. The flaw may exist in various components of SharePoint including web services, API endpoints, or administrative interfaces where privilege checks are either absent or bypassed. According to CWE classification, this vulnerability aligns with CWE-285 which specifically addresses insufficient authorization issues in software systems. The weakness creates a pathway for attackers to move laterally within the network and potentially gain access to additional resources that should remain protected.
The operational impact of this vulnerability extends beyond simple privilege escalation, as it can enable comprehensive system compromise when combined with other attack vectors. An attacker who successfully exploits this flaw could potentially access confidential business data, manipulate SharePoint content, or establish persistent access to the environment. The vulnerability particularly affects organizations using Microsoft Office SharePoint Server and SharePoint Online platforms where users may have legitimate access but lack proper privilege controls. This creates a significant risk for enterprise environments where SharePoint serves as a central collaboration and document management platform. The ability to escalate privileges without detection makes this vulnerability particularly dangerous from a security perspective.
Organizations should implement multiple layers of defense to mitigate this type of authorization flaw in SharePoint environments. Immediate remediation efforts should focus on applying Microsoft security updates and patches that address the specific privilege escalation mechanism. Configuration reviews should ensure proper access control policies are enforced throughout the SharePoint infrastructure, including implementing role-based access controls and regular permission audits. Network segmentation strategies can help limit the potential impact if an attacker successfully exploits this vulnerability by restricting lateral movement within the environment. From a detection perspective, security monitoring solutions should be configured to identify unusual privilege escalation activities or unauthorized access attempts to administrative functions. The ATT&CK framework categorizes this type of vulnerability under privilege escalation techniques where adversaries leverage authorization flaws to gain elevated system privileges, making it essential for security teams to monitor for such activities as part of their defensive posture. Regular security assessments and penetration testing should be conducted to identify similar authorization weaknesses that could provide attackers with additional attack vectors within the SharePoint ecosystem.