CVE-2026-68582 in vikunja
Summary
by MITRE • 08/02/2026
Vikunja versions >= 0.24.0 and <= 2.3.0 contain a broken object level authorization (BOLA) vulnerability in the task-collection endpoint (GET /api/v1/projects/{project}/views/{view}/tasks). The endpoint loads the requested project view from the URL path without verifying the caller is authorized for it. For a link-share token holder, the task scope is pinned to the share's own project, but the view is taken from the attacker-controlled path and never re-validated. As a result, a holder of any project share link can read any other tenant's kanban bucket records — bucket titles and the full created_by user object (username, name, id) — for every view in the instance. The same missing pre-authorization view load also creates a project/view-ID existence oracle (404 vs. non-404) usable by link shares and ordinary authenticated users. Task contents remain constrained to the share's own project and are not disclosed. Fixed in 2.4.0.
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Analysis
by VulDB Data Team • 08/02/2026
The vulnerability identified in Vikunja versions between 0.24.0 and 2.3.0 represents a critical broken object level authorization issue that fundamentally compromises the application's access control mechanisms. This weakness exists within the task-collection endpoint at GET /api/v1/projects/{project}/views/{view}/tasks where the system fails to properly validate user authorization before processing requests. The flaw manifests when link-share token holders attempt to access project views through attacker-controlled path parameters, creating a dangerous scenario where legitimate users can bypass intended access restrictions.
The technical implementation of this vulnerability stems from an improper authorization check during the view loading process. When a request arrives at the endpoint, the system retrieves the project view directly from the URL path without performing a comprehensive authorization verification. This design flaw allows malicious actors to manipulate the view parameter while maintaining their valid link-share token, effectively enabling them to traverse the application's object hierarchy beyond their intended scope. The vulnerability specifically affects the kanban bucket records which contain sensitive information including bucket titles and complete user objects with username, name, and id fields.
The operational impact of this vulnerability extends far beyond simple data exposure, creating a comprehensive information disclosure threat that affects multiple tenants within the same instance. A single link-share token holder can potentially access any tenant's kanban bucket records regardless of project boundaries, fundamentally undermining the multi-tenant security model. The exposure includes not only bucket titles but also complete user identification information through the created_by field, which provides attackers with valuable reconnaissance data for potential further exploitation. Additionally, the missing pre-authorization check creates an existence oracle that allows attackers to distinguish between valid and invalid project or view IDs through 404 response codes, providing additional attack surface information.
This vulnerability aligns with CWE-285, which addresses improper authorization issues in software systems, and maps to ATT&CK technique T1078 for Valid Accounts and T1566 for Phishing, as it exploits legitimate access tokens to gain unauthorized access to information. The flaw demonstrates a classic case of insufficient input validation combined with inadequate authorization enforcement, where the system trusts path parameters without proper verification against user permissions or tenant boundaries. The root cause lies in the application's failure to implement proper object-level access controls during the view retrieval process, allowing arbitrary view IDs to be processed without authorization checks.
The security implications are particularly severe given that this vulnerability affects all link-share token holders and authenticated users alike, creating a universal threat vector that requires no special privileges to exploit. While task contents remain properly constrained to the share's own project, the exposure of bucket titles and user information provides attackers with significant contextual intelligence about other tenants' organizational structures and personnel. The fix implemented in version 2.4.0 addresses this by enforcing proper authorization checks before loading any view data, ensuring that all path parameters are validated against the user's actual permissions and tenant boundaries. Organizations using affected versions should immediately implement mitigation strategies including access control reviews, monitoring for unauthorized access patterns, and prompt upgrade to patched versions to prevent potential exploitation of this critical authorization bypass vulnerability.