CVE-2026-39111: Apartment Visitors Management SQLi Flaw

CVE-2026-39111 Overview

CVE-2026-39111 is a SQL injection vulnerability in PHP Gurukul Apartment Visitors Management System version 1.1. The flaw resides in the email parameter of the forgot-password.php page. Unauthenticated attackers can inject crafted SQL syntax into the parameter and manipulate backend database queries. Successful exploitation allows extraction of sensitive user data, including stored credentials and personal information of residents and administrators. The vulnerability is classified under CWE-89: Improper Neutralization of Special Elements used in an SQL Command. No authentication or user interaction is required, and the attack is exploitable over the network against any exposed instance of the application.

Critical Impact

Unauthenticated remote attackers can extract sensitive database contents from any internet-facing deployment of the Apartment Visitors Management System v1.1 by manipulating SQL queries through the password reset form.

Affected Products

• PHP Gurukul Apartment Visitors Management System v1.1
• The forgot-password.php endpoint within the application
• Deployments using the unpatched MySQL backend distributed with the project

Discovery Timeline

• 2026-04-20 - CVE-2026-39111 published to NVD
• 2026-04-20 - Last updated in NVD database

Technical Details for CVE-2026-39111

Vulnerability Analysis

The Apartment Visitors Management System is an open-source PHP and MySQL application distributed by PHP Gurukul for managing apartment visitor records. The forgot-password.php page accepts an email parameter from an HTTP POST request and uses it to query the user table for a matching account. The application concatenates this user-supplied value directly into a SQL statement without parameterization or input sanitization. An attacker submits crafted input through the password reset form to alter the structure of the executed query. Because the endpoint is accessible before authentication, no credentials are required to reach the vulnerable code path. The attacker reads arbitrary data from any table accessible to the database user, including hashed credentials, contact details, and visitor records.

Root Cause

The root cause is direct concatenation of untrusted input into a SQL query string within forgot-password.php. The application does not use prepared statements, parameter binding, or input validation on the email field. This pattern matches [CWE-89] and is consistent with other SQL injection issues reported against PHP Gurukul applications.

Attack Vector

The attack vector is network-based through standard HTTP requests. An attacker sends a POST request to forgot-password.php with a SQL payload in the email parameter. Typical exploitation uses UNION-based or boolean-based blind injection techniques to enumerate database schema and exfiltrate rows. The vulnerability impacts confidentiality only; integrity and availability of database contents are not directly affected by the documented attack path.

No verified public exploit code is available at this time. Refer to the GitHub CVE Repository for technical details published by the reporter.

Detection Methods for CVE-2026-39111

Indicators of Compromise

• HTTP POST requests to /forgot-password.php containing SQL metacharacters such as single quotes, UNION SELECT, SLEEP(, --, or /* in the email parameter
• Web server access logs showing repeated requests to the forgot password endpoint from a single source within short time windows
• Database error messages or unusually large response sizes returned from forgot-password.php
• Unexpected outbound traffic from the database host following requests to the password reset page

Detection Strategies

• Deploy web application firewall rules that inspect the email POST parameter on forgot-password.php for SQL syntax patterns
• Enable MySQL general query logging temporarily to capture queries containing concatenated SQL syntax originating from the application user
• Correlate web server logs with database query logs to identify requests that generated abnormally complex SELECT statements

Monitoring Recommendations

• Monitor for high-volume or time-delayed requests to forgot-password.php that suggest blind SQL injection probing
• Alert on database queries executed by the application account that reference system tables such as information_schema.tables or information_schema.columns
• Track failed and successful password reset attempts and flag sources generating disproportionate traffic to the endpoint

How to Mitigate CVE-2026-39111

Immediate Actions Required

• Restrict public network access to the Apartment Visitors Management System until a fixed version is available, using IP allowlisting or VPN-only access
• Deploy a web application firewall rule that blocks SQL metacharacters in the email parameter of forgot-password.php
• Rotate database credentials and force password resets for all application users if exploitation is suspected
• Audit the database for unauthorized read activity and review recent web server logs for injection patterns

Patch Information

At the time of publication, no vendor patch is referenced in the NVD entry for CVE-2026-39111. Monitor the PHP Gurukul Project Overview page for updated releases and apply any newer version that addresses the SQL injection in forgot-password.php. When a fix becomes available, replace the affected file and verify that prepared statements are used for all database access.

Workarounds

• Modify forgot-password.php to use parameterized queries with mysqli_prepare() or PDO prepared statements instead of string concatenation
• Add server-side input validation that rejects non-email characters in the email field before any database interaction
• Configure the database account used by the application with read-only access limited to required tables to reduce data exposure if injection occurs
• Disable the forgot password feature entirely until a code-level fix is applied if the function is not operationally required

# Example WAF rule (ModSecurity) to block SQL syntax in the email parameter
SecRule ARGS:email "@rx (?i)(union(\s|/\*.*\*/)+select|sleep\s*\(|--|;|/\*|\bor\b\s+1=1)" \
    "id:1039111,phase:2,deny,status:403,msg:'CVE-2026-39111 SQLi attempt on forgot-password.php'"