Description

Improper input validation in Microsoft Office SharePoint allows an unauthorized attacker to execute code over a network.

Executive Summary

Technical Details

Mitigations

References

Additional Metadata

{
  "score": "8.1",
  "pubDate": "2026-08-11T17:18:47.377Z",
  "pubdate": "2026-08-11T17:18:47.377Z",
  "executiveSummary": "An improper input validation vulnerability has been identified within Microsoft Office SharePoint, presenting severe security implications for enterprise environments. This security flaw enables an unauthorized, network-based threat actor to achieve arbitrary remote code execution on vulnerable target servers without requiring prior authentication or user interaction.\nThe primary vulnerability type involves insufficient sanitization and validation of user-supplied input handled by the affected Microsoft Office SharePoint component. By sending crafted malicious payloads across the network, an attacker can manipulate application logic, resulting in memory corruption or insecure deserialization conditions that facilitate the execution of arbitrary system commands.\nThe impact of successful exploitation is critical, potentially granting the adversary full control over the underlying host system, leading to unauthorized data exfiltration, lateral movement within the enterprise network, and deployment of secondary payloads such as ransomware or persistent backdoors.\nExploitation requirements are minimal regarding authentication, as the flaw can be leveraged by unauthenticated remote attackers. Organizations utilizing vulnerable versions of Microsoft Office SharePoint face elevated risk levels due to the inherent exposure of collaboration platforms to internal and external networks, necessitating immediate triage and remediation efforts.",
  "technicalDetails": "The vulnerability stems from improper input validation mechanisms implemented within the request parsing and processing routines of Microsoft Office SharePoint. When the application receives inbound network traffic containing serialized objects or structured parameters, it fails to adequately verify the boundaries, type definitions, and structural integrity of the supplied data before ingestion.\nThe root cause lies in insecure handling of input streams within the vulnerable component, which allows maliciously constructed input to bypass security controls and reach internal APIs or execution handlers. Attackers leverage this weakness by crafting specialized payloads designed to exploit underlying logic flaws, such as unsafe object deserialization or improper buffer management during parsing operations.\nThe attack flow proceeds as follows: First, the unauthorized attacker identifies the network endpoint exposed by Microsoft Office SharePoint that handles the flawed input processing logic. Second, the adversary crafts a malicious payload encapsulating arbitrary execution commands or shellcode designed to manipulate the application execution flow. Third, the payload is transmitted over the network via standard protocols to the vulnerable target endpoint.\nUpon receipt, the Microsoft Office SharePoint application processes the unsanitized input without conducting rigorous validation checks. The failure to validate the input structure triggers the underlying flaw, allowing the embedded payload to alter memory states or execute system-level commands within the context of the service account.\nThe affected components involve internal parsing engines and communication interfaces responsible for handling client requests within Microsoft Office SharePoint. Authentication requirements are nonexistent, as the vulnerability can be triggered remotely by unauthenticated entities over the network, lowering the barrier to entry for malicious actors.\nPrivilege requirements are dictated by the service account under which the vulnerable Microsoft Office SharePoint instance executes, frequently granting elevated permissions to the attacker upon successful exploitation. Post-exploitation impact includes complete system compromise, unauthorized access to sensitive document repositories, modification of system configurations, and potential pivot points to compromise adjacent network segments."
}