CVE-2025-11556 identifies a SQL Injection vulnerability in the Simple Leave Manager 1.0 application developed by code-projects. The vulnerability resides in the /user.php file where the 'table' argument is improperly sanitized, allowing an attacker to inject malicious SQL code remotely without requiring authentication or user interaction. This injection flaw can be exploited to manipulate backend database queries, potentially exposing sensitive employee leave data, modifying records, or disrupting application availability. The CVSS 4.0 vector indicates network attack vector (AV:N), low attack complexity (AC:L), no privileges required (PR:N), and no user interaction (UI:N), with limited impact on confidentiality, integrity, and availability (VC:L, VI:L, VA:L). Although no active exploitation in the wild is reported, a public exploit exists, increasing the risk of attacks. The vulnerability affects only version 1.0 of Simple Leave Manager, which is a specialized HR management tool used primarily for leave tracking. The lack of patches or official remediation guidance increases the urgency for organizations to implement defensive measures. The vulnerability's exploitation could lead to unauthorized data disclosure, data tampering, or denial of service conditions, impacting organizational operations and compliance with data protection regulations.

For European organizations, this vulnerability poses a risk to the confidentiality and integrity of employee leave and HR data managed by Simple Leave Manager 1.0. Unauthorized access or modification of such data could lead to privacy violations under GDPR, reputational damage, and operational disruptions in HR processes. Although the impact on availability is limited, attackers could potentially disrupt leave management workflows, affecting workforce planning. The remote and unauthenticated nature of the exploit increases the threat level, especially for organizations exposing the application to external networks or lacking proper network segmentation. Given the specialized nature of the software, the overall scope is limited to organizations using this product, but those affected may face compliance and legal risks due to data breaches. The absence of known active exploitation reduces immediate risk but the availability of a public exploit necessitates proactive mitigation.

European organizations using Simple Leave Manager 1.0 should immediately assess exposure of the /user.php endpoint and restrict access via network controls such as firewalls or VPNs. Implement strict input validation and sanitization on all user-supplied parameters, especially the 'table' argument, to prevent injection attacks. Where possible, refactor database queries to use parameterized statements or prepared queries to eliminate direct injection vectors. Limit database user permissions to the minimum necessary to reduce potential damage from exploitation. Monitor logs for suspicious SQL query patterns or unusual access attempts targeting the vulnerable endpoint. If vendor patches or updates become available, prioritize their deployment. Additionally, conduct security awareness training for administrators managing the application to recognize and respond to potential exploitation attempts. Consider isolating the application within a segmented network zone to limit lateral movement in case of compromise.