CVE-2026-70326
Summary
by MITRE • 08/11/2026
Server-side request forgery (ssrf) in Microsoft Office SharePoint allows an authorized attacker to elevate privileges over a network.
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Analysis
by VulDB Data Team • 08/11/2026
Server-side request forgery vulnerabilities in Microsoft Office SharePoint represent a critical class of security flaws that can enable unauthorized privilege escalation and lateral movement within corporate networks. This specific vulnerability arises from insufficient validation of user-supplied input when processing requests that are intended to be executed on the server side. The flaw allows an authenticated attacker to manipulate the application's behavior by redirecting requests to internal network resources that would otherwise be inaccessible to external parties. When SharePoint processes certain API calls or web service requests, it fails to properly sanitize or validate the target URLs that are passed as parameters, creating opportunities for attackers to craft malicious requests that can traverse internal network boundaries.
The technical implementation of this vulnerability typically involves manipulation of URL parameters within SharePoint's web services or REST APIs that handle external resource access. Attackers can exploit this by crafting specially formatted requests that cause the SharePoint server to make HTTP requests to internal systems such as internal web applications, database servers, or other network services. The vulnerability is particularly dangerous because SharePoint servers often run with elevated privileges and may have access to sensitive internal resources that are not exposed to external networks. This creates a pathway for attackers to bypass traditional network segmentation controls and gain access to systems that should be protected behind firewalls or network boundaries.
The operational impact of this vulnerability extends beyond simple data exfiltration, as it can enable attackers to perform privilege escalation attacks by leveraging the elevated permissions that SharePoint servers typically possess. When combined with other vulnerabilities or attack vectors, an attacker could potentially compromise entire internal networks through a single compromised SharePoint instance. The vulnerability may also facilitate reconnaissance activities where attackers use the SSRF capabilities to map internal network topology, identify running services, or discover sensitive system information. This reconnaissance phase can significantly increase the effectiveness of subsequent attacks and reduce the time required for privilege escalation or data theft operations.
Organizations should implement multiple layers of defense to mitigate this type of vulnerability, including strict input validation on all user-supplied parameters, network segmentation controls, and monitoring for unusual outbound network requests from SharePoint servers. The implementation of web application firewalls and network access controls can help prevent unauthorized internal resource access attempts. Additionally, regular security assessments and penetration testing should include specific checks for SSRF vulnerabilities in SharePoint environments, as these flaws often remain undetected until exploited in the wild. Security teams must also ensure that SharePoint instances are regularly updated with the latest security patches and that proper configuration management practices are maintained to minimize the attack surface exposed by these types of vulnerabilities.
This vulnerability aligns with CWE-918 which specifically addresses server-side request forgery, and relates to ATT&CK technique T1071.004 for application layer protocol usage in network communication. Organizations should review their SharePoint configurations against Microsoft's security guidance and consider implementing additional monitoring controls to detect anomalous behavior patterns that may indicate exploitation attempts. The vulnerability demonstrates the importance of proper input validation and the principle of least privilege when designing web applications, particularly those with elevated system permissions that can access internal network resources.