CVE-2026-6193: PHPGurukul Expense Tracking SQL Injection

CVE-2026-6193 Overview

A SQL Injection vulnerability has been identified in PHPGurukul Daily Expense Tracking System version 1.1. The vulnerability exists in an unknown function of the file /register.php, where improper sanitization of the email argument allows attackers to inject malicious SQL commands. This flaw can be exploited remotely without authentication, and the exploit has been publicly disclosed, increasing the risk of active exploitation.

Critical Impact

Remote attackers can manipulate database queries through the email parameter in the registration functionality, potentially leading to unauthorized data access, data modification, or complete database compromise.

Affected Products

• PHPGurukul Daily Expense Tracking System 1.1

Discovery Timeline

• April 13, 2026 - CVE-2026-6193 published to NVD
• April 13, 2026 - Last updated in NVD database

Technical Details for CVE-2026-6193

Vulnerability Analysis

This SQL Injection vulnerability (CWE-74: Improper Neutralization of Special Elements in Output Used by a Downstream Component) affects the registration functionality of the PHPGurukul Daily Expense Tracking System. The vulnerability stems from insufficient input validation and sanitization when processing the email parameter in /register.php.

When a user submits registration data, the application directly incorporates the email field value into SQL queries without proper parameterization or escaping. This allows an attacker to craft malicious input containing SQL syntax that alters the intended query logic, potentially enabling unauthorized access to sensitive database contents, modification of existing records, or bypassing authentication mechanisms entirely.

Root Cause

The root cause is improper input validation and lack of parameterized queries in the registration handler. The email parameter is directly concatenated into SQL statements without sanitization, creating an injection point that attackers can exploit to execute arbitrary SQL commands against the underlying database.

Attack Vector

The attack can be launched remotely over the network without requiring any prior authentication or user interaction. An attacker can craft a malicious HTTP request to the /register.php endpoint containing SQL injection payloads in the email parameter. Due to the public availability of the exploit, attackers can readily leverage this vulnerability to target vulnerable installations.

The attack flow typically involves:

1. Attacker identifies a vulnerable PHPGurukul Daily Expense Tracking System instance
2. Attacker crafts a registration request with SQL injection payload in the email field
3. The application processes the malicious input without sanitization
4. The injected SQL commands execute against the database
5. Attacker retrieves sensitive data or manipulates database contents

Detection Methods for CVE-2026-6193

Indicators of Compromise

• Unusual SQL error messages in application logs related to /register.php
• Abnormal database queries containing SQL keywords (UNION, SELECT, OR, AND) in the email field
• Multiple failed registration attempts from the same source IP with varied payloads
• Database access logs showing unexpected SELECT or UNION operations during registration

Detection Strategies

• Deploy Web Application Firewall (WAF) rules to detect SQL injection patterns in POST requests to /register.php
• Monitor application logs for SQL syntax errors or database exception messages
• Implement intrusion detection signatures for common SQL injection payloads targeting the email parameter
• Enable database query logging and alert on queries containing injection indicators

Monitoring Recommendations

• Set up real-time alerts for SQL error patterns in web server logs
• Monitor network traffic for suspicious requests to the /register.php endpoint
• Implement rate limiting on registration endpoints to detect automated exploitation attempts
• Review database audit logs for unauthorized data access or modification patterns

How to Mitigate CVE-2026-6193

Immediate Actions Required

• Restrict access to the /register.php endpoint if registration functionality is not actively needed
• Implement Web Application Firewall rules to filter SQL injection payloads
• Consider temporarily disabling the registration feature until a patch is available
• Review database permissions and ensure the application uses a least-privilege database account

Patch Information

No official patch has been released by the vendor at the time of publication. Organizations should monitor PHP Gurukul's website for security updates. Technical details and community discussion are available through the GitHub CVE Issue Discussion and VulDB Vulnerability #357115.

Workarounds

• Implement input validation on the server side to reject email inputs containing SQL metacharacters
• Use prepared statements with parameterized queries for all database operations
• Deploy a Web Application Firewall with SQL injection detection enabled
• Restrict network access to the application to trusted IP ranges only

# Example WAF rule for ModSecurity to block SQL injection in email parameter
SecRule ARGS:email "@detectSQLi" \
    "id:100001,\
    phase:2,\
    deny,\
    status:403,\
    log,\
    msg:'SQL Injection attempt detected in email parameter',\
    logdata:'Matched Data: %{MATCHED_VAR}'"