Vulnerability 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 Score
CRITICAL
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Streetwriters | Notesnook Desktop | < 3.3.11 |
| Streetwriters | Notesnook Mobile | < 3.3.17 |
Related Weaknesses (CWE)
References
- https://github.com/streetwriters/notesnook/security/advisories/GHSA-f42f-phvp-43ExploitVendor Advisory
FAQ
What is CVE-2026-33976?
CVE-2026-33976 is a vulnerability with a CVSS score of 9.6 (CRITICAL). 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 deskto...
How severe is CVE-2026-33976?
CVE-2026-33976 has been rated CRITICAL with a CVSS base score of 9.6/10. This is considered a critical vulnerability requiring immediate attention.
Is there a patch for CVE-2026-33976?
Check the references section above for vendor advisories and patch information. Affected products include: Streetwriters Notesnook Desktop, Streetwriters Notesnook Mobile.