CVE-2026-30842 is a vulnerability classified under CWE-862 (Missing Authorization) affecting Wallos, an open-source, self-hostable personal subscription tracker. The flaw exists in versions prior to 4.6.2, where the avatar deletion endpoint fails to verify that the avatar file requested for deletion belongs to the authenticated user making the request. This missing authorization check allows any authenticated user to delete avatar files uploaded by other users if they can guess or discover the filename. The vulnerability does not require user interaction beyond authentication and can be exploited remotely over the network. The impact is limited to integrity, as attackers can remove or tamper with user avatar images but cannot access or modify other sensitive data or disrupt service availability. The CVSS v3.1 base score is 4.3, reflecting low complexity and privileges required but limited impact scope. The vulnerability was publicly disclosed on March 7, 2026, and patched in Wallos version 4.6.2. No known exploits have been reported in the wild. The flaw highlights the importance of enforcing strict authorization checks on user-specific resources in multi-user applications.

The primary impact of this vulnerability is the unauthorized deletion of user avatar files, which compromises data integrity for affected users. While this does not affect confidentiality or availability, it can degrade user experience and trust in the platform. In environments where user avatars are important for identity or branding, such unauthorized deletions could cause reputational damage or user dissatisfaction. Since exploitation requires authentication, the threat is limited to insiders or registered users, reducing the risk of widespread abuse. However, in organizations or communities with many users, an attacker could target multiple users’ avatars, causing broader disruption. The vulnerability does not enable access to sensitive data or system control, so the overall risk is moderate. Nonetheless, failure to patch could lead to persistent integrity issues and potential escalation if combined with other vulnerabilities.

The definitive mitigation is to upgrade Wallos to version 4.6.2 or later, where the authorization check on avatar deletion is properly enforced. Until upgrade is possible, administrators should restrict user permissions to minimize the risk of unauthorized file deletions, such as limiting who can upload or delete avatars. Monitoring logs for unusual deletion requests and implementing rate limiting on avatar deletion endpoints can help detect and prevent abuse. Additionally, users should be educated to use strong, non-guessable filenames for uploaded avatars to reduce the chance of filename discovery. Application developers should review all endpoints handling user-specific resources to ensure proper authorization checks are in place, following the principle of least privilege. Regular security audits and penetration testing can help identify similar authorization issues before release.