Vulnerability record · CVE-2026-33976 · published 27 March 2026
CVE-2026-33976: Streetwriters notesnook desktop cross-site scripting vulnerability
Streetwriters · Notesnook Desktop
Notesnook is a note-taking app. Prior to version 3.3.11 on Web/Desktop and 3.3.17 on Android/iOS, a stored XSS in the Web Clipper rendering flow can be escalated to remote code execution in the desktop app. The root cause is that the clipper preserves attacker-controlled attributes from the source page’s root element and stores them inside web-clip HTML. When the clip is later opened, Notesnook renders that HTML into a same-origin, unsandboxed iframe using `contentDocument.write(...)`. Event-handler attributes such as `onload`, `onclick`, or `onmouseover` execute in the Notesnook origin. In the desktop app, this becomes RCE because Electron is configured with `nodeIntegration: true` and `contextIsolation: false`. Version 3.3.11 Web/Desktop and 3.3.17 on Android/iOS patch the issue.
Description
Notesnook is a note-taking app. Prior to version 3.3.11 on Web/Desktop and 3.3.17 on Android/iOS, a stored XSS in the Web Clipper rendering flow can be escalated to remote code execution in the desktop app. The root cause is that the clipper preserves attacker-controlled attributes from the source page’s root element and stores them inside web-clip HTML. When the clip is later opened, Notesnook renders that HTML into a same-origin, unsandboxed iframe using `contentDocument.write(...)`. Event-handler attributes such as `onload`, `onclick`, or `onmouseover` execute in the Notesnook origin. In the desktop app, this becomes RCE because Electron is configured with `nodeIntegration: true` and `contextIsolation: false`. Version 3.3.11 Web/Desktop and 3.3.17 on Android/iOS patch the issue.
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H
Affected products
2 vulnerable configurations from NVD's CPE data, grouped by vendor and product.
References
| Link | Tags |
|---|---|
| https://github.com/streetwriters/notesnook/security/advisories/GHSA-f42f-phvp-43x5 | ExploitVendor Advisory |
Track CVE-2026-33976 inside VULONE
Watch it alongside the ransomware crews, C2 infrastructure and forum chatter that reference it, query it through the API and pull it into your SIEM over TAXII.
Related vulnerabilities
Same products first, then exploited flaws of the same weakness class.
Source: NIST National Vulnerability Database (record CVE-2026-33976), CISA KEV, FIRST EPSS (scores of 2026-09-26). This page is refreshed as NVD updates the record.
