CVE-2026-33955 Notesnook vulnerable to RCE via stored XSS in Note History diff viewer
Attackers can achieve remote code execution in the Notesnook desktop app via stored XSS in the note history viewer due to insecure HTML rendering and Electron configuration.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Local or same network only
- Victim action needed
- A user has to click or open something
- Fix
- None listed
What is CVE-2026-33955?
CVE-2026-33955 is a high-severity cross-site scripting vulnerability in streetwriters Notesnook Web/Desktop, published on 27 Mar 2026. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.
Official description
Notesnook is a note-taking app. Prior to version 3.3.11 on Web/Desktop, a cross-site scripting vulnerability stored in the note history comparison viewer can escalate to remote code execution in a desktop application. The issue is triggered when an attacker-controlled note header is displayed using `dangerouslySetInnerHTML` without secure handling. When combined with the full backup and restore feature in the desktop application, this becomes remote code execution because Electron is configured with `nodeIntegration: true` and `contextIsolation: false`. Version 3.3.11 patches the issue.
Which versions are affected by CVE-2026-33955?
It affects 1 product.
Products include Streetwriters Notesnook Desktop.
How do I fix CVE-2026-33955?
No fix has been published for CVE-2026-33955 yet. Limit exposure of the affected software until one is available.
Escape output for the context it lands in and set a strict Content Security Policy. Upgrading the affected component is the real fix. More about Cross-site scripting.
Is CVE-2026-33955 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-33955 exists.
Other vulnerabilities in streetwriters Notesnook Web/Desktop
Sources
Also known as GHSA-45g3-cv93-q59v.