CVE-2026-42090

Notesnook: RCE via stored XSS in note export rendering

Published May 4, 2026 CVSS 3.1 · 9.6 Critical EPSS < 1% KEV · Not listed
Description
Notesnook is a note-taking app focused on user privacy & ease of use. Prior to Notesnook Web/Desktop version 3.3.15 and prior to Notesnook iOS/Android version 3.3.20, a stored XSS vulnerability in the note export flow can be escalated to remote code execution in the desktop app. The root cause is that exported note fields such as title, headline, and content are inserted into the generated HTML template without HTML escaping. When the note is later exported to PDF, Notesnook renders that HTML into a same-origin, unsandboxed iframe using iframe.srcdoc = .... Injected script executes in the Notesnook origin. In the desktop app, this becomes RCE because Electron is configured with nodeIntegration: true and contextIsolation: false. This issue has been patched in Notesnook Web/Desktop version 3.3.15 and Notesnook iOS/Android version 3.3.20.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

No advisories available
History
Type Values Removed Values Added
First Time appeared Streetwriters notesnook Desktop
Streetwriters notesnook Mobile
CPEs cpe:2.3:a:streetwriters:notesnook_desktop:*:*:*:*:*:*:*:*
cpe:2.3:a:streetwriters:notesnook_mobile:*:*:*:*:*:android:*:*
cpe:2.3:a:streetwriters:notesnook_mobile:*:*:*:*:*:iphone_os:*:*
Vendors & Products Streetwriters notesnook Desktop
Streetwriters notesnook Mobile
Type Values Removed Values Added
First Time appeared Streetwriters
Streetwriters notesnook
Vendors & Products Streetwriters
Streetwriters notesnook
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'total'}, 'version': '2.0.3'}

Type Values Removed Values Added
Description Notesnook is a note-taking app focused on user privacy & ease of use. Prior to Notesnook Web/Desktop version 3.3.15 and prior to Notesnook iOS/Android version 3.3.20, a stored XSS vulnerability in the note export flow can be escalated to remote code execution in the desktop app. The root cause is that exported note fields such as title, headline, and content are inserted into the generated HTML template without HTML escaping. When the note is later exported to PDF, Notesnook renders that HTML into a same-origin, unsandboxed iframe using iframe.srcdoc = .... Injected script executes in the Notesnook origin. In the desktop app, this becomes RCE because Electron is configured with nodeIntegration: true and contextIsolation: false. This issue has been patched in Notesnook Web/Desktop version 3.3.15 and Notesnook iOS/Android version 3.3.20.
Title Notesnook: RCE via stored XSS in note export rendering
Weaknesses CWE-79
CWE-94
References
Metrics cvssV3_1

{'score': 9.6, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
GitHub_M
Published
Updated
May 5, 2026, 3:56 AM
Reserved
Apr 23, 2026, 7:17 PM
Status
Analyzed
Published
May 4, 2026, 5:16 PM
Modified
Oct 26, 2026, 7:10 PM