CVE-2026-31877: Frappe Framework SQL Injection Vulnerability

CVE-2026-31877 Overview

CVE-2026-31877 is a SQL Injection vulnerability affecting the Frappe full-stack web application framework. Prior to versions 15.84.0 and 14.99.0, a specially crafted request made to a certain endpoint could result in SQL injection, allowing an attacker to extract sensitive information from the database that they would not otherwise be authorized to access.

Critical Impact

This SQL injection vulnerability enables unauthenticated remote attackers to extract sensitive data from Frappe-based applications, potentially exposing user credentials, business data, and other confidential information stored in the database.

Affected Products

• Frappe Framework versions prior to 15.84.0
• Frappe Framework versions prior to 14.99.0 (LTS branch)

Discovery Timeline

• 2026-03-11 - CVE-2026-31877 published to NVD
• 2026-03-12 - Last updated in NVD database

Technical Details for CVE-2026-31877

Vulnerability Analysis

This vulnerability is classified as CWE-89: Improper Neutralization of Special Elements used in an SQL Command (SQL Injection). The Frappe framework, a popular Python-based web application framework used to build business applications including ERPNext, contains an endpoint that fails to properly sanitize user-supplied input before incorporating it into SQL queries.

SQL injection vulnerabilities occur when user input is concatenated directly into SQL statements without proper parameterization or escaping. In this case, an attacker can craft malicious HTTP requests to the vulnerable endpoint, injecting SQL syntax that alters the intended query logic. This allows the attacker to bypass access controls and retrieve data from the database that should not be accessible.

The vulnerability is network-accessible with no authentication required, meaning any remote attacker can exploit this flaw without needing valid credentials to the Frappe application. The impact primarily affects confidentiality and integrity of the data, as attackers can read and potentially modify database contents.

Root Cause

The root cause of this vulnerability is improper input validation and lack of parameterized queries in the affected endpoint. User-supplied data is incorporated directly into SQL query strings rather than being passed as parameters to prepared statements, allowing SQL metacharacters to be interpreted as part of the query structure rather than as literal data values.

Attack Vector

The attack is conducted over the network by sending specially crafted HTTP requests to the vulnerable endpoint. The attacker constructs malicious input containing SQL syntax such as single quotes, UNION statements, or boolean-based payloads to manipulate the underlying SQL query.

Depending on the specific injection point and database configuration, attackers may employ various SQL injection techniques including:

• UNION-based injection to combine results from unauthorized tables
• Boolean-based blind injection to infer data one bit at a time through response differences
• Time-based blind injection using database sleep functions to extract data
• Error-based injection leveraging verbose error messages to reveal data

For detailed technical information about the vulnerable endpoint and exploitation mechanics, see the GitHub Security Advisory.

Detection Methods for CVE-2026-31877

Indicators of Compromise

• Unusual database queries in application logs containing SQL keywords like UNION, SELECT, or DROP
• HTTP requests with SQL metacharacters (single quotes, double dashes, semicolons) in parameters
• Database error messages appearing in web server logs indicating malformed queries
• Unexpected data access patterns or bulk data extraction from the database

Detection Strategies

• Deploy Web Application Firewall (WAF) rules to detect and block SQL injection patterns in HTTP requests
• Enable and monitor Frappe application logs for suspicious query patterns or database errors
• Implement runtime application self-protection (RASP) solutions to detect SQL injection attempts
• Configure database audit logging to track unusual SELECT queries or unauthorized table access

Monitoring Recommendations

• Monitor database performance metrics for anomalous query patterns indicating data exfiltration
• Review web server access logs for requests containing encoded SQL injection payloads
• Set up alerts for database authentication failures or unauthorized schema access attempts
• Track network egress for large data transfers that may indicate successful exploitation

How to Mitigate CVE-2026-31877

Immediate Actions Required

• Upgrade Frappe Framework to version 15.84.0 or later (or 14.99.0 for LTS users)
• Review application logs for evidence of exploitation attempts
• Conduct a database audit to identify any unauthorized data access
• Implement WAF rules to block SQL injection patterns as a defense-in-depth measure

Patch Information

Frappe has released security patches addressing this vulnerability in versions 15.84.0 and 14.99.0. Organizations running vulnerable versions should upgrade immediately. The fix implements proper input sanitization and parameterized queries for the affected endpoint. Patch details and release notes are available in the GitHub Security Advisory.

Workarounds

• Deploy a Web Application Firewall with SQL injection detection rules in front of Frappe applications
• Restrict network access to the Frappe application to trusted IP ranges where possible
• Implement database user permissions following least-privilege principles to limit exposure
• Enable verbose logging and monitoring to detect exploitation attempts until patching is complete

# Example: Upgrade Frappe using bench
cd frappe-bench
bench update --apps frappe
bench migrate
bench restart