CVE-2026-12775: Montodel House-Rental SQLI Vulnerability

CVE-2026-12775 Overview

CVE-2026-12775 is a SQL injection vulnerability in Montodel House-Rental-Management affecting the /login.php endpoint. The flaw resides in the handling of the Username parameter, which is concatenated into a SQL query without proper sanitization. An unauthenticated remote attacker can manipulate this parameter to alter query logic and access or modify backend data. The exploit details are public, increasing the risk of opportunistic attacks. The product follows a rolling release model, so no fixed version identifier exists. The vendor was contacted prior to disclosure but did not respond. This issue is classified under [CWE-74] (Improper Neutralization of Special Elements in Output Used by a Downstream Component).

Critical Impact
Unauthenticated remote attackers can execute arbitrary SQL queries through the login form, potentially exposing credentials and rental management data.

Affected Products

Montodel House-Rental-Management up to commit 90010017b81265eb1ef3810268909f7719a33863
Rolling release builds prior to any post-disclosure remediation
Deployments exposing /login.php to untrusted networks

Discovery Timeline

2026-06-21 - CVE-2026-12775 published to NVD
2026-06-23 - Last updated in NVD database

Technical Details for CVE-2026-12775

Vulnerability Analysis

The vulnerability exists in the authentication logic of /login.php in Montodel House-Rental-Management. The application accepts the Username parameter from the login form and incorporates it into a SQL statement without parameterization or input validation. An attacker can submit crafted input containing SQL metacharacters to break out of the intended string context and inject arbitrary clauses.

Because the injection point sits in the pre-authentication login flow, exploitation requires no credentials. Attackers can use classic payloads such as tautology-based bypass strings or UNION-based extraction to read arbitrary tables. The impact extends across confidentiality, integrity, and availability of the backend database, though the scope remains limited to the rental application's data store.

The public availability of exploit details, combined with the vendor's lack of response, leaves all deployments exposed until administrators implement compensating controls.

Root Cause

The root cause is improper neutralization of special elements in a downstream SQL component [CWE-74]. The Username value flows directly from the HTTP POST body into a dynamically constructed SQL query. The code does not use prepared statements, parameter binding, or escaping routines appropriate for the database driver in use.

Attack Vector

The attack vector is network-based and requires no authentication or user interaction. An attacker sends a POST request to /login.php with a malicious Username value. The injected SQL executes within the database context used by the application, enabling data extraction, authentication bypass, or modification of stored records depending on backend privileges.

No verified proof-of-concept code is included here. Technical details are referenced in the GitHub Issue on CVE-2026-12775 and the VulDB Vulnerability Detail.

Detection Methods for CVE-2026-12775

Indicators of Compromise

POST requests to /login.php containing SQL metacharacters such as single quotes, --, UNION, OR 1=1, or SLEEP( in the Username field
Unusual database error messages returned from the login endpoint in web server logs
Repeated failed login attempts from a single source followed by sudden success without a valid credential pattern
Spikes in outbound database response sizes correlated with login traffic

Detection Strategies

Inspect web access logs for anomalous Username parameter values containing encoded or raw SQL syntax
Enable database query logging and alert on queries originating from the login flow that contain UNION, INFORMATION_SCHEMA, or boolean tautologies
Deploy a web application firewall with SQL injection signatures tuned for the /login.php path

Monitoring Recommendations

Continuously monitor authentication endpoints for input patterns that deviate from expected username character classes
Correlate web server, application, and database telemetry to identify injection attempts that bypass perimeter filtering
Alert on backend database errors surfaced through the login response body or HTTP status codes

How to Mitigate CVE-2026-12775

Immediate Actions Required

Restrict network access to the Montodel House-Rental-Management application to trusted networks or VPN until a fix is available
Deploy a web application firewall rule blocking SQL metacharacters in the Username parameter of /login.php
Review database logs for evidence of prior exploitation and rotate any credentials stored within the application database
Reduce database account privileges used by the application to the minimum required for normal operation

Patch Information

No official vendor patch is available. The vendor did not respond to disclosure attempts, and the product uses a rolling release model without versioned releases. Administrators should monitor the upstream repository referenced in the GitHub Issue on CVE-2026-12775 for community-supplied fixes and apply parameterized queries in /login.php where feasible.

Workarounds

Modify /login.php to use prepared statements with parameter binding instead of string concatenation
Apply server-side input validation that restricts Username to an allowlisted character set
Place the application behind an authenticating reverse proxy to remove unauthenticated exposure of the login form

bash

# Example ModSecurity rule blocking common SQLi patterns on /login.php
SecRule REQUEST_URI "@streq /login.php" \
    "phase:2,chain,deny,status:403,id:1012775,msg:'CVE-2026-12775 SQLi attempt'"
    SecRule ARGS:Username "@rx (?i)(\b(union|select|or|and)\b.*\b(select|from|where)\b|--|;|'|\")" \
        "t:none,t:urlDecodeUni"