Vikunja is an open-source self-hosted task management platform. Prior to 2.3.0, Vikunja's scoped API token enforcement for custom project background routes is method-confused. A token with only projects.background can successfully delete a project background, while a token with only projects.background_delete is rejected. This is a scoped-token authorization bypass. This vulnerability is fixed in 2.3.0.
Vikunja is an open-source self-hosted task management platform. Prior to 2.3.0, the Vikunja file import endpoint uses the attacker-controlled Size field from the JSON metadata inside the import zip instead of the actual decompressed file content length for the file size enforcement check. By setting Size to 0 in the JSON while including large compressed file entries in the zip, an attacker bypasses the configured maximum file size limit. This vulnerability is fixed in 2.3.0.
Vikunja is an open-source self-hosted task management platform. Prior to 2.3.0, the CalDAV output generator builds iCalendar VTODO entries via raw string concatenation without applying RFC 5545 TEXT value escaping. User-controlled task titles containing CRLF characters break the iCalendar property boundary, allowing injection of arbitrary iCalendar properties such as ATTACH, VALARM, or ORGANIZER. This vulnerability is fixed in 2.3.0.
Vikunja is an open-source self-hosted task management platform. Prior to 2.3.0, task titles are embedded directly into Markdown link syntax in overdue email notifications without escaping Markdown special characters. When rendered by goldmark and sanitized by bluemonday (which allows <a> and <img> tags), injected Markdown constructs produce phishing links and tracking pixels in legitimate notification emails. This vulnerability is fixed in 2.3.0.
Vikunja is an open-source self-hosted task management platform. Prior to 2.3.0, the addRepeatIntervalToTime function uses an O(n) loop that advances a date by the task's RepeatAfter duration until it exceeds the current time. By creating a repeating task with a 1-second interval and a due date far in the past, an attacker triggers billions of loop iterations, consuming CPU and holding a database connection for minutes per request. This vulnerability is fixed in 2.3.0.
Vikunja is an open-source self-hosted task management platform. Prior to 2.3.0, the CalDAV GetResource and GetResourcesByList methods fetch tasks by UID from the database without verifying that the authenticated user has access to the task's project. Any authenticated CalDAV user who knows (or guesses) a task UID can read the full task data from any project on the instance. This vulnerability is fixed in 2.3.0.
Vikunja is an open-source self-hosted task management platform. Prior to 2.3.0, the TOTP failed-attempt lockout mechanism is non-functional due to a database transaction handling bug. When a TOTP validation fails, the login handler in pkg/routes/api/v1/login.go calls HandleFailedTOTPAuth and then unconditionally rolls back. HandleFailedTOTPAuth in pkg/user/totp.go uses an in-memory counter (key-value store) to track failed attempts. When the counter reaches 10, it calls user.SetStatus(s, StatusAccountLocked) on the same database session s. Because the login handler always rolls back after a TOTP failure, the StatusAccountLocked write is undone. The in-memory counter correctly increments past 10, so the lockout code executes on every subsequent attempt, but the database write is rolled back every time. This allows unlimited brute-force attempts against TOTP codes. This vulnerability is fixed in 2.3.0.
Vikunja is an open-source self-hosted task management platform. Prior to 2.3.0, the hasAccessToLabel function contains a SQL operator precedence bug that allows any authenticated user to read any label that has at least one task association, regardless of project access. Label titles, descriptions, colors, and creator information are exposed. This vulnerability is fixed in 2.3.0.
Vikunja is an open-source self-hosted task management platform. Prior to 2.3.0, the CanUpdate check at pkg/models/project_permissions.go:139-148 only requires CanWrite on the new parent project when changing parent_project_id. However, Vikunja's permission model uses a recursive CTE that walks up the project hierarchy to compute permissions. Moving a project under a different parent changes the permission inheritance chain. When a user has inherited Write access (from a parent project share) and reparents the child project under their own project tree, the CTE resolves their ownership of the new parent as Admin (permission level 2) on the moved project. This vulnerability is fixed in 2.3.0.
Vikunja is an open-source self-hosted task management platform. Prior to 2.3.0, Vikunja's link share authentication (GetLinkShareFromClaims in pkg/models/link_sharing.go) constructs authorization objects entirely from JWT claims without any server-side database validation. When a project owner deletes a link share or downgrades its permissions, all previously issued JWTs continue to grant the original permission level for up to 72 hours (the default service.jwtttl). This vulnerability is fixed in 2.3.0.
Vikunja is an open-source self-hosted task management platform. Prior to 2.3.0, the OIDC callback handler issues a full JWT token without checking whether the matched user has TOTP two-factor authentication enabled. When a local user with TOTP enrolled is matched via the OIDC email fallback mechanism, the second factor is completely skipped. This vulnerability is fixed in 2.3.0.
Vikunja is an open-source self-hosted task management platform. Prior to version 2.2.1, the `DELETE /api/v1/projects/:project/shares/:share` endpoint does not verify that the link share belongs to the project specified in the URL. An attacker with admin access to any project can delete link shares from other projects by providing their own project ID combined with the target share ID. Version 2.2.1 patches the issue.
Vikunja is an open-source self-hosted task management platform. Prior to version 2.2.2, the `LinkSharing.ReadAll()` method allows link share authenticated users to list all link shares for a project, including their secret hashes. While `LinkSharing.CanRead()` correctly blocks link share users from reading individual shares via `ReadOne`, the `ReadAllWeb` handler bypasses this check by never calling `CanRead()`. An attacker with a read-only link share can retrieve hashes for write or admin link shares on the same project and authenticate with them, escalating to full admin access. Version 2.2.2 patches the issue.
Vikunja is an open-source self-hosted task management platform. Prior to version 2.2.1, the `DownloadImage` function in `pkg/utils/avatar.go` uses a bare `http.Client{}` with no SSRF protection when downloading user avatar images from the OpenID Connect `picture` claim URL. An attacker who controls their OIDC profile picture URL can force the Vikunja server to make HTTP GET requests to arbitrary internal or cloud metadata endpoints. This bypasses the SSRF protections that are correctly applied to the webhook system. Version 2.2.1 patches the issue.
Vikunja is an open-source self-hosted task management platform. Prior to version 2.2.1, `TaskAttachment.ReadOne()` queries attachments by ID only (`WHERE id = ?`), ignoring the task ID from the URL path. The permission check in `CanRead()` validates access to the task specified in the URL, but `ReadOne()` loads a different attachment that may belong to a task in another project. This allows any authenticated user to download or delete any attachment in the system by providing their own accessible task ID with a target attachment ID. Attachment IDs are sequential integers, making enumeration trivial. Version 2.2.1 patches the issue.
Vikunja is an open-source self-hosted task management platform. Prior to version 2.2.1, the `GET /api/v1/projects/:project/webhooks` endpoint returns webhook BasicAuth credentials (`basic_auth_user` and `basic_auth_password`) in plaintext to any user with read access to the project. While the existing code correctly masks the HMAC `secret` field, the BasicAuth fields added in a later migration were not given the same treatment. This allows read-only collaborators to steal credentials intended for authenticating against external webhook receivers. Version 2.2.1 patches the issue.
Vikunja is an open-source self-hosted task management platform. Prior to version 2.2.1, when the Vikunja API returns tasks, it populates the `related_tasks` field with full task objects for all related tasks without checking whether the requesting user has read permission on those tasks' projects. An authenticated user who can read a task that has cross-project relations will receive full details (title, description, due dates, priority, percent completion, project ID, etc.) of tasks in projects they have no access to. Version 2.2.1 patches the issue.
Vikunja is an open-source self-hosted task management platform. Prior to version 2.2.1, the migration helper functions `DownloadFile` and `DownloadFileWithHeaders` in `pkg/modules/migration/helpers.go` make arbitrary HTTP GET requests without any SSRF protection. When a user triggers a Todoist or Trello migration, file attachment URLs from the third-party API response are passed directly to these functions, allowing an attacker to force the Vikunja server to fetch internal network resources and return the response as a downloadable task attachment. Version 2.2.1 patches the issue.
Vikunja is an open-source self-hosted task management platform. Starting in version 0.18.0 and prior to version 2.2.1, when a user account is disabled or locked, the status check is only enforced on the local login and JWT token refresh paths. Three other authentication paths — API tokens, CalDAV basic auth, and OpenID Connect — do not verify user status, allowing disabled or locked users to continue accessing the API and syncing data. Version 2.2.1 patches the issue.
Vikunja is an open-source self-hosted task management platform. Starting in version 1.0.0-rc0 and prior to version 2.2.0, unbounded image decoding and resizing during preview generation lets an attacker exhaust CPU and memory with highly compressed but extremely large-dimension images. Version 2.2.0 patches the issue.