CVE-2025-7104 is a mass assignment vulnerability classified under CWE-915 (Improperly Controlled Modification of Dynamically-Determined Object Attributes) found in the danny-avila/librechat project. The vulnerability arises because the application automatically binds user-supplied data from request bodies to internal object properties or database fields without adequate filtering or validation. This allows attackers to inject additional fields that are not intended to be user-modifiable, such as author, access_level, isCollaborative, and projectIds, effectively overwriting these sensitive attributes. Furthermore, the use of Object.assign combined with spread operators in the codebase leads to Object Prototype Pollution, which can alter the prototype chain of JavaScript objects, potentially causing unexpected behavior or security bypasses. The vulnerability affects all versions of librechat, with no specific patched versions indicated yet. According to the CVSS 3.0 vector, the attack vector is network-based (AV:N), requires no privileges (PR:N), but does require user interaction (UI:R). The impact is limited to confidentiality loss (C:L), with no direct impact on integrity or availability. No known exploits have been reported in the wild as of the publication date. The vulnerability could allow attackers to gain unauthorized access to sensitive data or escalate privileges within the application by manipulating access controls and project associations. The root cause is insufficient input validation and unsafe object property assignment patterns in the code.

For European organizations using danny-avila/librechat, this vulnerability could lead to unauthorized disclosure of sensitive information due to improper access control modifications. Attackers could manipulate project ownership, collaboration flags, or access levels, potentially exposing confidential project data or internal communications. This is particularly concerning for organizations relying on librechat for collaborative or project management purposes where data confidentiality is critical. Although the vulnerability does not directly impact data integrity or system availability, the confidentiality breach could result in reputational damage, regulatory non-compliance (e.g., GDPR violations), and subsequent financial penalties. The requirement for user interaction means phishing or social engineering could be used to trigger exploitation, increasing the risk in environments with less security awareness. Since no known exploits exist yet, the immediate risk is moderate, but the potential for future exploitation remains. European entities with sensitive intellectual property or regulated data are at higher risk of impact.

To mitigate this vulnerability, organizations should implement strict server-side input validation and enforce a whitelist of allowed fields that can be modified via user input, rejecting any unexpected or extra fields in request bodies. Developers should avoid using Object.assign with spread operators on untrusted input to prevent prototype pollution; instead, use safer object merging techniques or libraries designed to handle this securely. Applying patches or updates from the vendor once available is critical. In the interim, code audits should be conducted to identify and refactor unsafe object property assignments. Employing runtime application self-protection (RASP) or web application firewalls (WAF) with custom rules to detect and block suspicious payloads targeting mass assignment or prototype pollution patterns can provide additional defense. User education to recognize phishing attempts can reduce the likelihood of successful exploitation requiring user interaction. Finally, monitoring logs for anomalous changes to sensitive fields and implementing strict access controls on database operations can help detect and limit the impact of exploitation.