CVE-2026-33336

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&amp;#39;s machine. Version 2.2.0 patches the issue.<br /> <br /> ## Root cause<br /> <br /> Two misconfigurations combine to create this vulnerability:<br /> <br /> 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.).<br /> <br /> 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:<br /> - `` links (without `target="_blank"`)<br /> - `window.location` assignments<br /> - HTTP redirects<br /> - `` tags<br /> <br /> ## Attack scenario<br /> <br /> 1. The attacker is a normal user on the same Vikunja instance (e.g., a member of a shared project).<br /> 2. The attacker creates or edits a project description or task description containing a standard HTML link, e.g.: `Click here for the updated design spec`<br /> 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.<br /> 4. The victim uses Vikunja Desktop and clicks the link.<br /> 5. Because no `will-navigate` handler exists, the BrowserWindow navigates to `https://evil.example/exploit` in the same renderer process.<br /> 6. The attacker&amp;#39;s page now executes in a context with `nodeIntegration: true` and runs: `require(&amp;#39;child_process&amp;#39;).exec(&amp;#39;id &gt; /tmp/pwned&amp;#39;);`<br /> 7. Arbitrary commands execute as the victim&amp;#39;s OS user.<br /> <br /> ## Impact<br /> <br /> Full remote code execution on the victim&amp;#39;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.<br /> <br /> ## Proof of concept<br /> <br /> 1. Set up a Vikunja instance with two users sharing a project.<br /> 2. As the attacker user, edit a project description to include: `Meeting notes`<br /> 3. Host poc.html with: `require(&amp;#39;child_process&amp;#39;).exec(&amp;#39;calc.exe&amp;#39;)`<br /> 4. As the victim, open the project in Vikunja Desktop and click the link.<br /> 5. calc.exe (or any other command) executes on the victim&amp;#39;s machine.<br /> <br /> ## Credits<br /> <br /> This vulnerability was found using [GitHub Security Lab Taskflows](https://github.com/GitHubSecurityLab/seclab-taskflows).