CVE-2026-0591: Online Product Reservation System SQLi Flaw

CVE-2026-0591 Overview

A SQL injection vulnerability has been identified in code-projects Online Product Reservation System version 1.0. The vulnerability exists in the Cart Update Handler component, specifically within the /app/checkout/update.php file. Attackers can exploit this flaw by manipulating the id and qty parameters to inject malicious SQL statements, potentially allowing unauthorized access to database contents, data modification, or other database-level attacks.

Critical Impact

Remote attackers with low-level privileges can exploit this SQL injection vulnerability to manipulate database queries, potentially extracting sensitive data or compromising database integrity.

Affected Products

• code-projects Online Product Reservation System 1.0
• Applications using the vulnerable /app/checkout/update.php Cart Update Handler

Discovery Timeline

• January 5, 2026 - CVE-2026-0591 published to NVD
• January 8, 2026 - Last updated in NVD database

Technical Details for CVE-2026-0591

Vulnerability Analysis

This SQL injection vulnerability (CWE-74: Injection) affects the Cart Update Handler in the Online Product Reservation System. The vulnerability allows remote authenticated attackers to inject arbitrary SQL statements through the id and qty parameters in the checkout update functionality. The exploit has been publicly documented and proof-of-concept code is available, increasing the risk of active exploitation.

The vulnerability is network-accessible, requiring only low-privilege authentication to exploit. When successfully exploited, attackers can achieve limited impact on confidentiality, integrity, and availability of the affected system. The attack does not require user interaction and can be performed with low complexity.

Root Cause

The root cause of this vulnerability is improper input validation and sanitization of user-supplied data in the /app/checkout/update.php file. The id and qty parameters are directly incorporated into SQL queries without proper escaping, parameterization, or validation. This classic input validation failure allows attackers to break out of the intended query structure and inject malicious SQL commands.

Attack Vector

The attack vector is network-based, allowing remote exploitation. An authenticated attacker can manipulate the id and qty parameters in HTTP requests to the /app/checkout/update.php endpoint. By crafting malicious input containing SQL metacharacters and statements, the attacker can alter the logic of database queries executed by the application.

The vulnerable parameters accept user input that is then used to construct SQL queries for updating cart items during the checkout process. Without proper input sanitization, special characters such as single quotes, double dashes, and SQL keywords are interpreted as SQL syntax rather than literal data values.

For detailed exploitation techniques and proof-of-concept code, refer to the GitHub PoC Documentation.

Detection Methods for CVE-2026-0591

Indicators of Compromise

• Anomalous database query patterns or errors in application logs related to the checkout update functionality
• HTTP requests to /app/checkout/update.php containing SQL metacharacters (single quotes, semicolons, comment sequences) in the id or qty parameters
• Unexpected database read/write operations or query execution timing anomalies
• Database error messages exposed in HTTP responses indicating SQL syntax errors

Detection Strategies

• Deploy web application firewall (WAF) rules to detect SQL injection patterns in the id and qty parameters
• Implement database activity monitoring to identify suspicious query patterns or unauthorized data access
• Configure application logging to capture all requests to /app/checkout/update.php for security review
• Enable SQL error logging and alerting on unexpected query failures

Monitoring Recommendations

• Monitor web server access logs for requests to /app/checkout/update.php with encoded or unusual parameter values
• Track database query execution times for anomalies that may indicate SQL injection-based time delays
• Review authentication logs for accounts making repeated requests to the vulnerable endpoint
• Implement real-time alerting on WAF SQL injection detection events

How to Mitigate CVE-2026-0591

Immediate Actions Required

• Restrict access to the /app/checkout/update.php endpoint to trusted networks or users only
• Implement a web application firewall with SQL injection protection rules
• Review and audit all instances of the Online Product Reservation System in your environment
• Consider temporarily disabling the cart update functionality until a patch is available

Patch Information

No official vendor patch information is currently available for this vulnerability. Organizations should monitor the code-projects website for security updates. The vulnerability was assigned VulDB #339501 and additional tracking information is available through VulDB CTI.

Workarounds

• Implement input validation to restrict the id parameter to numeric values only
• Use parameterized queries or prepared statements for all database operations involving user input
• Apply the principle of least privilege to database accounts used by the application
• Deploy network-level access controls to limit exposure of the vulnerable endpoint

# Example: Basic input validation for the vulnerable parameters
# Add to update.php or a security middleware

# Validate id parameter is numeric only
if [[ ! "$id" =~ ^[0-9]+$ ]]; then
    echo "Invalid id parameter"
    exit 1
fi

# Validate qty parameter is numeric only
if [[ ! "$qty" =~ ^[0-9]+$ ]]; then
    echo "Invalid qty parameter"
    exit 1
fi