CVE-2026-1134 identifies a cross-site scripting (XSS) vulnerability in itsourcecode Society Management System version 1.0, specifically within the /admin/expenses.php file. The vulnerability arises from improper sanitization or validation of the 'detail' parameter, allowing an attacker to inject malicious JavaScript code. This injection can be executed remotely without authentication, although it requires user interaction to trigger the payload, such as an administrator clicking a crafted link or viewing manipulated content. The XSS flaw can be exploited to perform actions like session hijacking, defacement, or redirecting users to malicious sites, potentially compromising the confidentiality and integrity of the affected system. The CVSS 4.0 vector indicates network attack vector (AV:N), low attack complexity (AC:L), no privileges required (PR:N), but user interaction is necessary (UI:P). The vulnerability does not impact availability or system confidentiality significantly but poses a risk to data integrity and user trust. No patches or official fixes have been published yet, and while no active exploitation in the wild is reported, a public exploit is available, increasing the likelihood of future attacks. The vulnerability primarily affects version 1.0 of the software, which is used for managing society or community expenses, making it a target for attackers aiming to disrupt or manipulate community financial data or gain unauthorized access to administrative functions.

For European organizations using the itsourcecode Society Management System 1.0, this vulnerability could lead to unauthorized script execution within the context of the admin interface, potentially allowing attackers to hijack administrator sessions, steal sensitive information, or manipulate displayed data. This could undermine trust in community management platforms and lead to financial mismanagement or data leakage. The impact is particularly significant for organizations managing sensitive community or society financial data, as attackers could leverage the XSS to perform phishing or social engineering attacks against administrators. While the vulnerability does not directly affect system availability, the indirect consequences of compromised administrative accounts or data integrity could disrupt operations. Given the remote exploitability and lack of required privileges, the threat is accessible to a wide range of attackers, increasing risk exposure. European entities with limited cybersecurity resources or those relying heavily on this software without additional protective controls are at higher risk. The medium severity rating reflects moderate potential damage but emphasizes the need for timely remediation to prevent escalation or chaining with other vulnerabilities.

To mitigate CVE-2026-1134, organizations should implement strict input validation and output encoding on the 'detail' parameter within /admin/expenses.php to prevent injection of malicious scripts. Employing a robust Content Security Policy (CSP) can help restrict the execution of unauthorized scripts. Access to the admin interface should be limited using network segmentation, VPNs, or IP whitelisting to reduce exposure. Administrators should be trained to recognize suspicious links or inputs that could trigger XSS attacks. Regular security audits and code reviews of the Society Management System should be conducted to identify and remediate similar vulnerabilities. If possible, upgrade to a patched version once available or apply custom patches to sanitize inputs. Implementing multi-factor authentication (MFA) for admin accounts can reduce the impact of session hijacking. Additionally, monitoring web logs for unusual activity related to the 'detail' parameter can provide early detection of exploitation attempts. Finally, organizations should maintain up-to-date backups and incident response plans tailored to web application attacks.