CVE-2026-33976: streetwriters Notesnook Web/Desktop · Cross-site Scripting
Affects streetwriters Notesnook Web/DesktopSource CVE Database V5
Not known to be exploited · CVSS 9.7 Critical : upgrade to 3.3.11 as a priority.
Data as of 30 Oct 2026, 11:52 UTC
- EPSS
- 0.7% chance of exploitation in 30 days – higher than 53% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 3.3.11, 3.3.17
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 27 Mar 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 30 Oct 2026.
What to do
Upgrade Notesnook Web/Desktop and streetwriters/notesnook to 3.3.11; Notesnook iOS/Android to 3.3.17.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| streetwritersNotesnook Web/Desktop | Affected
| Fixed in
|
| streetwritersNotesnook iOS/Android | Affected
| Fixed in
|
GitHubstreetwriters/notesnookpkg:github/streetwriters/notesnookOther threats | Affected
| Fixed in
|
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
The vendor has released official patches that fix this vulnerability in Notesnook Web/Desktop version 3.3.11 and Android/iOS version 3.3.17. Users and administrators should upgrade to these versions or later to remediate the issue. Since this is not a cloud service, remediation depends on applying these updates. Patch status is confirmed by the vendor advisory embedded in the description. No additional mitigation steps are indicated beyond applying the official updates.
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.