CVE-2026-108452 in SharePoint Server
Summary
by MITRE • 10/16/2026
Improper limitation of a pathname to a restricted directory ('path traversal') in Microsoft Office SharePoint allows an authorized attacker to execute code over a network.
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Analysis
by VulDB Data Team • 10/16/2026
The vulnerability described constitutes a critical path traversal flaw within the Microsoft Office SharePoint platform, specifically categorized under CWE-22: Improper Limitation of a Pathname to a Restricted Directory. This class of vulnerabilities arises when software constructs file paths or URLs using user-supplied input without adequately validating that the resulting path remains confined to an intended secure directory structure. In this specific instance, the flaw allows for remote code execution over a network by authorized attackers who can manipulate file system references to access resources outside their permitted scope. The core technical failure lies in the insufficient sanitization of pathname inputs, which permits sequences such as dot-dot-slash (../) or other platform-specific traversal characters to escape the designated root directory and reach sensitive areas of the server's file system.
From an operational perspective, this vulnerability poses a severe risk because it bridges the gap between authorized access and arbitrary code execution. While the attacker is required to be authenticated, which aligns with many enterprise security models where internal users are trusted, the ability to traverse directories undermines the principle of least privilege within the application layer. By exploiting this flaw, an attacker can potentially read configuration files that contain database credentials or API keys, access proprietary source code, or overwrite critical system binaries if write permissions allow. The ultimate impact is a complete compromise of the SharePoint server's integrity and confidentiality, as well as potential lateral movement into other parts of the internal network depending on how the compromised host interacts with adjacent systems.
This vulnerability maps directly to MITRE ATT&CK technique T1083: File and Directory Discovery, where adversaries explore the file system to gather information for further exploitation. Furthermore, it relates to T1564: Hidden Files and Directories if the attacker uses traversal to access hidden files that are not visible through standard directory listings. The attack vector is typically remote via HTTP or HTTPS requests targeting specific SharePoint endpoints that handle file uploads, downloads, or metadata operations without strict path validation. This allows for automated exploitation tools to systematically probe for valid paths by testing various combinations of relative and absolute path manipulations against the vulnerable service components.
Mitigation strategies must focus on both immediate remediation and long-term architectural improvements. The primary defense is applying the official security patches released by Microsoft, which address the input validation logic within the affected SharePoint modules. Administrators should ensure that all systems are updated to the latest cumulative updates containing these fixes. Beyond patching, implementing strict allow-lists for file names and paths can prevent traversal characters from being processed in any context. Additionally, running SharePoint services with minimal privileges ensures that even if path traversal occurs, the attacker cannot access files outside their specific user profile directory or modify system-level configurations. Network segmentation should also be enforced to limit the blast radius of a compromised server, ensuring that lateral movement is restricted by firewall rules and zero-trust principles.