Findings

CVE-2026-33336

Vikunja is an open-source self-hosted task management platform.

Published Mar 24, 2026 · updated Jun 17, 2026 · vikunja vikunja

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 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. ** ** is set in web preferences ( ), giving any page loaded in the renderer full access to Node.js APIs ( , , , etc.). 2. **No or handler** is registered on the . The existing ( ) only intercepts calls (new-window requests). It does **not** intercept same-window navigations triggered by: - links (without ) - assignments - HTTP redirects - 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.: 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: uses with DOMPurify-sanitized output. 4. The victim uses Vikunja Desktop and clicks the link. 5. Because no handler exists, the BrowserWindow navigates to in the same renderer process. 6. The attacker's page now executes in a context with and runs: 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. ##