CVE-2026-2158: Carmelo Student Web Portal SQLi Vulnerability

CVE-2026-2158 Overview

A SQL injection vulnerability has been identified in code-projects Student Web Portal version 1.0. This vulnerability affects the /check_user.php file, where improper handling of the Username argument allows attackers to inject malicious SQL statements. The vulnerability can be exploited remotely over the network without requiring authentication, potentially allowing unauthorized access to the underlying database and sensitive student information.

Critical Impact

Remote attackers can exploit this SQL injection vulnerability to bypass authentication, extract sensitive data from the student portal database, and potentially modify or delete records without authorization.

Affected Products

• Carmelo Student Web Portal 1.0
• code-projects Student Web Portal implementations using /check_user.php

Discovery Timeline

• 2026-02-08 - CVE-2026-2158 published to NVD
• 2026-02-11 - Last updated in NVD database

Technical Details for CVE-2026-2158

Vulnerability Analysis

This SQL injection vulnerability exists in the authentication mechanism of the Student Web Portal application. The /check_user.php file fails to properly sanitize or parameterize user input before incorporating it into SQL queries. When a user submits a username through the login form, the application directly concatenates this input into a SQL statement without proper validation or escaping.

The vulnerable endpoint processes authentication requests and uses the Username parameter in database queries. Since the input is not sanitized, an attacker can craft malicious input containing SQL metacharacters and commands that alter the intended query logic. This can lead to authentication bypass, data extraction through UNION-based or blind SQL injection techniques, and potential database manipulation.

Root Cause

The root cause of this vulnerability is the failure to implement parameterized queries or prepared statements when handling user-supplied input in the /check_user.php file. The application appears to use string concatenation to build SQL queries, directly inserting the Username parameter value into the query without sanitization. This violates secure coding practices and creates a classic SQL injection attack surface (CWE-89: Improper Neutralization of Special Elements used in an SQL Command).

Attack Vector

The attack can be initiated remotely over the network without requiring any prior authentication or user interaction. An attacker targets the /check_user.php endpoint by submitting a crafted Username parameter containing SQL injection payloads. The attack requires low complexity to execute, as standard SQL injection techniques can be applied.

Typical exploitation scenarios include:

• Authentication bypass: Injecting payloads that modify the WHERE clause logic to always return true
• Data exfiltration: Using UNION-based injection to retrieve data from other database tables
• Blind SQL injection: Inferring database contents through conditional responses when direct output is not available

For detailed technical analysis and proof-of-concept information, refer to the GitHub CVE SQL Analysis.

Detection Methods for CVE-2026-2158

Indicators of Compromise

• Unusual or malformed requests to /check_user.php containing SQL metacharacters (single quotes, double dashes, UNION, SELECT, OR statements)
• Authentication anomalies such as successful logins without valid credentials
• Database error messages appearing in application responses or logs
• Unexpected database queries in database audit logs containing injected SQL syntax

Detection Strategies

• Implement Web Application Firewall (WAF) rules to detect and block common SQL injection patterns targeting the Username parameter
• Monitor web server access logs for requests to /check_user.php containing suspicious characters or SQL keywords
• Deploy application-layer intrusion detection systems configured with SQL injection signature rules
• Enable database query logging and alert on queries containing unexpected syntax patterns

Monitoring Recommendations

• Set up real-time alerting for multiple failed authentication attempts followed by a successful login from the same source
• Monitor database audit logs for queries that deviate from expected patterns on user authentication tables
• Implement anomaly detection for unusually large data responses from the student portal application
• Review application error logs for SQL syntax errors that may indicate injection attempts

How to Mitigate CVE-2026-2158

Immediate Actions Required

• Remove or disable public access to the Student Web Portal application until the vulnerability is patched
• Implement a Web Application Firewall (WAF) with SQL injection detection rules as an interim protective measure
• Review database access logs for signs of exploitation and unauthorized data access
• Conduct a security assessment to identify any data breach resulting from potential exploitation

Patch Information

As of the last NVD update on 2026-02-11, no official vendor patch has been released for this vulnerability. Organizations using the affected Carmelo Student Web Portal 1.0 should monitor the Code Projects website and the VulDB Entry #344860 for patch availability. Consider implementing the workarounds below until an official fix is available.

Workarounds

• Implement input validation on the Username parameter to allow only alphanumeric characters and reject SQL metacharacters
• Modify the /check_user.php code to use prepared statements with parameterized queries instead of string concatenation
• Deploy network-level access controls to restrict access to the Student Web Portal to trusted IP ranges only
• Consider replacing the vulnerable authentication module with a secure implementation using an established security framework

# Example WAF rule for ModSecurity to block SQL injection attempts
SecRule ARGS:Username "@detectSQLi" \
    "id:100001,\
    phase:2,\
    deny,\
    status:403,\
    log,\
    msg:'SQL Injection attempt detected in Username parameter',\
    tag:'application-multi',\
    tag:'language-multi',\
    tag:'platform-multi',\
    tag:'attack-sqli',\
    tag:'CVE-2026-2158'"