CVE-2026-30842 in Wallos
Summary
by MITRE • 03/07/2026
Wallos is an open-source, self-hostable personal subscription tracker. Prior to version 4.6.2, Wallos allows an authenticated user to delete avatar files uploaded by other users. The avatar deletion endpoint does not verify that the requested avatar belongs to the current user. As a result, any authenticated user who knows or can discover another user's uploaded avatar filename can delete that file. This issue has been patched in version 4.6.2.
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Analysis
by VulDB Data Team • 03/12/2026
The vulnerability identified as CVE-2026-30842 affects Wallos, an open-source personal subscription tracking application designed for self-hosting environments. This authentication bypass issue stems from inadequate access control mechanisms within the avatar deletion functionality of the application. The flaw exists in versions prior to 4.6.2, where the system fails to properly validate user permissions when processing avatar deletion requests. The vulnerability represents a critical authorization flaw that undermines the fundamental security principles of user isolation and data protection within the application's file management system.
The technical implementation of this vulnerability occurs at the application's avatar deletion endpoint where the system accepts deletion requests without performing proper ownership verification. An authenticated user can exploit this weakness by discovering or enumerating the filenames of avatar images uploaded by other users and subsequently submitting deletion requests for those specific files. This type of vulnerability aligns with CWE-285, which describes improper authorization scenarios where systems fail to verify that the requesting entity has proper permissions to perform the requested operation. The lack of input validation and access control checks creates a direct path for privilege escalation through unauthorized file manipulation.
The operational impact of this vulnerability extends beyond simple data loss, as it enables authenticated attackers to disrupt other users' experiences within the application. Users who have uploaded avatars can have their profile images removed by malicious actors who gain access to the system, potentially causing confusion and undermining user trust in the application's data integrity. This issue particularly affects self-hosted environments where users may have varying levels of access and where proper sandboxing of user data is crucial for maintaining system security. The vulnerability can be exploited through reconnaissance techniques to discover valid avatar filenames, making it particularly dangerous in environments with limited monitoring of file system operations.
Mitigation strategies for this vulnerability involve implementing proper access control verification at the application's file management layer, ensuring that all deletion operations require explicit validation of user ownership before execution. The patch released in version 4.6.2 addresses this issue by enforcing user context validation during avatar deletion requests, preventing unauthorized access to files owned by other users. Organizations should also implement monitoring of file system operations, particularly around user-generated content, to detect and respond to unauthorized file modifications. From an ATT&CK framework perspective, this vulnerability relates to techniques involving privilege escalation and unauthorized data access, specifically covering the T1078 and T1566 tactics. Regular security updates and proper access control implementation remain essential for preventing similar authorization bypass scenarios in self-hosted applications.