CVE-2026-20947: SharePoint SQL Injection Vulnerability

CVE-2026-20947 Overview

CVE-2026-20947 is a SQL Injection vulnerability affecting Microsoft Office SharePoint that allows an authorized attacker to execute code over a network. This vulnerability arises from improper neutralization of special elements used in SQL commands (CWE-89), enabling attackers with valid credentials to manipulate database queries and potentially gain full control over the affected SharePoint environment.

Critical Impact

Authenticated attackers can exploit this SQL Injection flaw to execute arbitrary code on SharePoint servers, potentially compromising sensitive corporate data, internal documents, and the underlying server infrastructure.

Affected Products

• Microsoft Office SharePoint (specific versions not disclosed)

Discovery Timeline

• January 13, 2026 - CVE-2026-20947 published to NVD
• January 13, 2026 - Last updated in NVD database

Technical Details for CVE-2026-20947

Vulnerability Analysis

This vulnerability represents a classic SQL Injection flaw in Microsoft Office SharePoint where user-supplied input is not properly sanitized before being incorporated into SQL queries. The attack requires authenticated access to the SharePoint environment, meaning the attacker must possess valid credentials. However, once authenticated, the attacker can craft malicious SQL statements that bypass the application's intended query logic.

The exploitation path leverages SharePoint's database interaction layer, where specially crafted input can escape the intended SQL context and inject arbitrary SQL commands. This can lead to unauthorized data access, data modification, or in severe cases, execution of system commands through SQL Server's extended procedures.

Root Cause

The root cause of CVE-2026-20947 is improper neutralization of special characters in user input before constructing SQL queries. SharePoint fails to adequately sanitize or parameterize certain input fields, allowing SQL metacharacters such as single quotes, semicolons, and SQL keywords to be interpreted as part of the query structure rather than as literal data values. This enables attackers to break out of the intended query context and execute arbitrary SQL statements.

Attack Vector

The attack is conducted over the network by an authenticated user. The attacker submits specially crafted input through SharePoint's web interface or API endpoints that interact with the backend SQL database. The malicious input contains SQL syntax designed to alter the query's behavior, potentially allowing the attacker to:

1. Extract sensitive data from the database through UNION-based or error-based injection techniques
2. Modify or delete existing records, compromising data integrity
3. Escalate privileges within the database context
4. Execute stored procedures that may enable operating system command execution

The vulnerability does not require user interaction beyond the attacker's own authenticated session, making it straightforward to exploit once valid credentials are obtained.

Detection Methods for CVE-2026-20947

Indicators of Compromise

• Unusual SQL error messages appearing in SharePoint logs or exposed to users
• Database query logs containing SQL injection patterns such as UNION SELECT, '; DROP TABLE, or xp_cmdshell
• Unexpected database connections or queries originating from the SharePoint application pool
• Evidence of data exfiltration or unauthorized database modifications
• Authentication logs showing compromised accounts accessing SharePoint with unusual patterns

Detection Strategies

• Deploy Web Application Firewall (WAF) rules to detect and block SQL injection patterns in SharePoint traffic
• Enable SQL Server auditing to monitor for suspicious query patterns and stored procedure calls
• Implement SharePoint ULS log monitoring for SQL-related error messages and exceptions
• Configure SIEM correlation rules to detect sequences of failed injection attempts followed by successful exploitation
• Monitor for outbound data transfers that may indicate successful data exfiltration

Monitoring Recommendations

• Enable detailed logging for SharePoint database connections and queries
• Configure alerts for SQL Server authentication failures and privilege escalation attempts
• Monitor SharePoint application event logs for exceptions related to database operations
• Implement database activity monitoring to detect anomalous query patterns
• Review IIS logs for unusual parameter values in SharePoint web requests

How to Mitigate CVE-2026-20947

Immediate Actions Required

• Apply the Microsoft security update for CVE-2026-20947 immediately on all affected SharePoint servers
• Review and audit SharePoint user accounts to identify and disable any potentially compromised credentials
• Implement network segmentation to limit exposure of SharePoint servers from untrusted network segments
• Enable enhanced logging on SharePoint and SQL Server to support incident investigation

Patch Information

Microsoft has released a security update addressing CVE-2026-20947. Administrators should consult the Microsoft Security Update Guide for CVE-2026-20947 for detailed patching instructions, affected product versions, and download links. The patch addresses the SQL injection vulnerability by implementing proper input validation and parameterized queries.

Workarounds

• Implement strict input validation at the application layer for all SharePoint forms and API endpoints
• Deploy a Web Application Firewall (WAF) with SQL injection detection rules in front of SharePoint
• Restrict database permissions for the SharePoint application service account to minimum required privileges
• Disable dangerous SQL Server features such as xp_cmdshell if not required
• Consider placing SharePoint behind additional authentication layers while awaiting patch deployment