CVE-2026-103690: Leave Management System SQL Injection Flaw

CVE-2026-103690 Overview

CVE-2026-103690 is a SQL injection vulnerability in itsourcecode Leave Management System 1.0. The flaw resides in the /module/leave/controller.php file and is triggered through manipulation of the LEAVEID parameter. Remote attackers with low privileges can inject arbitrary SQL statements into database queries. The exploit has been publicly disclosed, which increases the likelihood of opportunistic abuse against exposed deployments. The vulnerability is classified under [CWE-74] (Improper Neutralization of Special Elements in Output Used by a Downstream Component).

Critical Impact
Authenticated remote attackers can inject SQL statements through the LEAVEID parameter in /module/leave/controller.php, allowing unauthorized read or modification of leave management records.

Affected Products

itsourcecode Leave Management System 1.0
Component: /module/leave/controller.php
Parameter: LEAVEID

Discovery Timeline

2026-10-01 - CVE-2026-103690 published to NVD
2026-10-01 - Last updated in NVD database

Technical Details for CVE-2026-103690

Vulnerability Analysis

The vulnerability exists in the leave management controller script shipped with itsourcecode Leave Management System 1.0. The LEAVEID parameter is passed directly from an HTTP request into a SQL statement without proper sanitization or parameterization. An authenticated remote attacker can supply crafted input that breaks out of the intended query context and executes attacker-controlled SQL.

Successful exploitation can expose leave records, modify or delete entries, and in some database configurations enable broader read access to adjacent tables. The exploit code has been published publicly, lowering the barrier to exploitation.

Root Cause

The root cause is improper neutralization of user-supplied input before it is used in a SQL query. The LEAVEID argument is concatenated into a query string rather than being bound as a parameter. This design pattern maps to [CWE-74] and is a textbook example of SQL injection in PHP applications that rely on string construction with the mysqli or mysql extensions.

Attack Vector

An attacker sends a crafted HTTP request to /module/leave/controller.php containing a malicious LEAVEID value. The attack is executed over the network and requires low-level authentication to the application. No user interaction is required. Because the exploit has been published, scanning for vulnerable instances and reusing the proof-of-concept payload is straightforward.

See the VulDB Vulnerability Report and the GitHub Issue Discussion for public exploit details.

Detection Methods for CVE-2026-103690

Indicators of Compromise

HTTP requests to /module/leave/controller.php containing SQL metacharacters such as single quotes, UNION SELECT, OR 1=1, or inline comments in the LEAVEID parameter.
Web server access logs showing abnormally long or encoded LEAVEID values from a single source IP.
Database error messages (for example SQLSTATE, mysqli_fetch, or syntax errors) correlated with requests to the leave controller.

Detection Strategies

Deploy web application firewall (WAF) rules that inspect the LEAVEID parameter for SQL injection signatures.
Enable database query logging and alert on malformed queries referencing the leave table.
Correlate authentication events with suspicious parameter manipulation to identify low-privileged accounts testing injection payloads.

Monitoring Recommendations

Monitor outbound connections from the application server for data exfiltration following injection attempts.
Review audit logs for unexpected SELECT, UPDATE, or DELETE operations against leave records.
Track repeat requests to /module/leave/controller.php with varying parameter values from the same session.

How to Mitigate CVE-2026-103690

Immediate Actions Required

Restrict network access to the Leave Management System to trusted internal networks until a patch is applied.
Audit all accounts with access to the application and disable unused or default credentials.
Deploy WAF signatures to block SQL injection payloads targeting the LEAVEID parameter.

Patch Information

No vendor patch has been published in the available advisories for itsourcecode Leave Management System 1.0 at the time of CVE publication. Operators should monitor the IT Source Code site and the VulDB CVE Details entry for updates.

Workarounds

Modify /module/leave/controller.php to use parameterized queries or prepared statements with bound parameters for the LEAVEID input.
Add server-side input validation that enforces a strict numeric type on the LEAVEID parameter before any database interaction.
Apply least-privilege database permissions so the application account cannot access unrelated tables or execute administrative statements.

bash

# Example WAF rule concept (ModSecurity) to block SQLi on LEAVEID
SecRule ARGS:LEAVEID "@detectSQLi" \
    "id:1030690,phase:2,deny,status:403,msg:'Possible SQLi on LEAVEID (CVE-2026-103690)'"