CVE-2025-13748 is an authorization bypass vulnerability classified under CWE-639 (Authorization Bypass Through User-Controlled Key) affecting the Fluent Forms – Customizable Contact Forms, Survey, Quiz, & Conversational Form Builder WordPress plugin by techjewel. The vulnerability exists in all versions up to and including 6.1.7 within the confirmScaPayment() function, where the 'submission_id' parameter is accepted from user input without proper validation. This parameter is used to identify form submissions, and due to the lack of authorization checks, an unauthenticated attacker can craft requests to the vulnerable endpoint to mark arbitrary submissions as failed. The attack surface is remote and requires no authentication or user interaction, relying on the ability to guess or enumerate valid submission IDs. While the vulnerability does not expose sensitive data or cause denial of service, it compromises the integrity of submission records by allowing unauthorized modification of their status. The CVSS v3.1 base score is 5.3 (medium), reflecting the ease of exploitation and limited impact scope. No patches were linked at the time of publication, and no exploits have been observed in the wild. The vulnerability is significant for organizations relying on Fluent Forms for critical data collection, as it could disrupt workflows, cause confusion, or be leveraged as part of a larger attack chain.

For European organizations, the primary impact of CVE-2025-13748 is the integrity compromise of form submission data within websites using the Fluent Forms plugin. This could lead to business process disruptions, such as lost or misrepresented survey results, contact requests, or quiz outcomes. While confidentiality and availability remain unaffected, the ability for unauthenticated attackers to alter submission statuses could undermine trust in data accuracy and potentially affect decision-making processes based on form inputs. Organizations in sectors like e-commerce, customer service, education, and public administration that rely heavily on online forms may experience operational inefficiencies or reputational damage. Additionally, attackers could use this vulnerability as a foothold to probe for further weaknesses or to disrupt user interactions. The lack of authentication and user interaction requirements increases the risk of automated exploitation attempts, especially if submission IDs are predictable or enumerable.

1. Monitor for updates from techjewel and apply security patches for Fluent Forms promptly once released. 2. Implement web application firewall (WAF) rules to restrict access to the confirmScaPayment() endpoint, limiting requests to trusted IPs or authenticated users where possible. 3. Employ rate limiting and anomaly detection to prevent enumeration or brute force attempts on submission IDs. 4. Review and harden the plugin’s configuration to minimize exposure of sensitive endpoints. 5. Conduct regular audits of form submission logs to detect unauthorized status changes. 6. Consider temporary disabling or replacing the plugin if immediate patching is not feasible and the risk is unacceptable. 7. Educate site administrators on the risks and signs of exploitation to enable rapid response. 8. Use security plugins or services that can detect and block suspicious HTTP requests targeting vulnerable parameters.