SB20260113125 - Multiple vulnerabilities in Microsoft SharePoint Server

Description

This security bulletin contains information about 3 secuirty vulnerabilities.

1) SQL injection (CVE-ID: CVE-2026-20947)

The vulnerability allows a remote attacker to execute arbitrary SQL queries in database.

The vulnerability exists due to insufficient sanitization of user-supplied data in Microsoft SharePoint Server. A remote user can send a specially crafted request to the affected application and execute arbitrary SQL commands within the application database.

Successful exploitation of this vulnerability may allow a remote attacker to read, delete, modify data in database and gain complete control over the affected application.

2) Input validation error (CVE-ID: CVE-2026-20951)

The vulnerability allows a remote attacker to execute arbitrary code on the target system.

The vulnerability exists due to insufficient validation of user-supplied input in Microsoft SharePoint Server. A remote attacker can trick a victim to open a specially crafted file and execute arbitrary code on the system.

3) Cross-site scripting (CVE-ID: CVE-2026-20959)

The disclosed vulnerability allows a remote attacker to perform cross-site scripting (XSS) attacks.

The vulnerability exists due to insufficient sanitization of user-supplied data in Microsoft SharePoint Server. A remote user can trick the victim to follow a specially crafted link and execute arbitrary HTML and script code in user's browser in context of vulnerable website.

Successful exploitation of this vulnerability may allow a remote attacker to steal potentially sensitive information, change appearance of the web page, perform phishing and drive-by-download attacks.

Remediation

Install update from vendor's website.

References

• https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-20947
• https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-20951
• https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-20959