CVE-2026-63512 in SharePoint Server
Summary
by MITRE • 08/11/2026
Incorrect authorization in Microsoft Office SharePoint allows an authorized attacker to perform tampering over a network.
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Analysis
by VulDB Data Team • 08/11/2026
This vulnerability represents a critical authorization flaw in Microsoft Office SharePoint that enables malicious actors with legitimate credentials to manipulate network resources through unauthorized data tampering operations. The issue stems from insufficient access controls within the SharePoint platform's permission architecture, allowing authenticated users to bypass expected security boundaries and modify content or system configurations they should not have access to.
The technical implementation of this vulnerability manifests when SharePoint fails to properly validate user permissions during network-based operations, particularly in scenarios involving document management, list modifications, or configuration changes. Attackers can exploit this weakness by leveraging their existing authorized sessions to execute unauthorized actions against shared resources, potentially leading to data corruption, privilege escalation, or complete system compromise.
From an operational perspective, the impact extends beyond simple data manipulation as it undermines the fundamental security model of SharePoint environments. Organizations may experience unauthorized content modification, loss of data integrity, and potential exposure of sensitive information when attackers exploit this authorization gap to alter documents, modify user permissions, or manipulate shared resources within the network infrastructure.
The vulnerability aligns with CWE-285, which addresses improper authorization within software systems, and maps to several ATT&CK tactics including privilege escalation and defense evasion. Security professionals should recognize this as a critical risk in enterprise collaboration platforms where SharePoint serves as the primary content management system for organizational data sharing and document collaboration.
Mitigation strategies must include implementing comprehensive access control reviews, enabling detailed auditing of user activities, deploying additional network segmentation measures, and ensuring proper configuration of SharePoint permission levels. Organizations should also consider implementing multi-factor authentication, regular security assessments, and continuous monitoring of user behavior patterns to detect anomalous activities that may indicate exploitation attempts. Additionally, maintaining up-to-date security patches from Microsoft and conducting regular vulnerability assessments specifically targeting SharePoint authorization mechanisms will significantly reduce the risk exposure associated with this class of vulnerabilities.