CVE-2026-42090
Notesnook: RCE via stored XSS in note export rendering
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.
INFO
Published Date :
May 4, 2026, 5:16 p.m.
Last Modified :
Oct. 26, 2026, 7:10 p.m.
Remotely Exploit :
Yes !
Source :
[email protected]
Affected Products
The following products are affected by CVE-2026-42090
vulnerability.
Even if cvefeed.io is aware of the exact versions of the
products
that
are
affected, the information is not represented in the table below.
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS | 134c704f-9b21-4f2e-91b3-4a467353bcc0 | |||||
| CVSS 3.1 | CRITICAL | [email protected] |
Solution
- Update Notesnook Web/Desktop to version 3.3.15.
- Update Notesnook iOS/Android to version 3.3.20.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-42090.
| URL | Resource |
|---|---|
| https://github.com/streetwriters/notesnook/releases/tag/3.3.20-android | Release Notes |
| https://github.com/streetwriters/notesnook/releases/tag/v3.3.15 | Release Notes |
| https://github.com/streetwriters/notesnook/security/advisories/GHSA-fjm8-jg78-89h4 | Vendor Advisory |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-42090 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-42090
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-42090 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-42090 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
CVE Translated by [email protected]
Oct. 26, 2026
Action Type Old Value New Value Added Translation Title: notesnook de streetwriters, Description: Notesnook es una aplicación para tomar notas centrada en la privacidad del usuario y la facilidad de uso. Antes de la versión 3.3.15 de Notesnook Web/Escritorio y antes de la versión 3.3.20 de Notesnook iOS/Android, una vulnerabilidad XSS almacenada en el flujo de exportación de notas puede escalarse a ejecución remota de código en la aplicación de escritorio. La causa raíz es que los campos de nota exportados como título, encabezado y contenido se insertan en la plantilla HTML generada sin escape HTML. Cuando la nota se exporta posteriormente a PDF, Notesnook renderiza ese HTML en un iframe de mismo origen y sin sandbox usando iframe.srcdoc = .... El script inyectado se ejecuta en el origen de Notesnook. En la aplicación de escritorio, esto se convierte en RCE porque Electron está configurado con nodeIntegration: true y contextIsolation: false. Este problema ha sido parcheado en la versión 3.3.15 de Notesnook Web/Escritorio y la versión 3.3.20 de Notesnook iOS/Android. -
CVE Modified by [email protected]
Jun. 17, 2026
Action Type Old Value New Value Added Affected [{'vendor': 'streetwriters', 'product': 'notesnook', 'versions': [{'status': 'affected', 'version': 'Notesnook Web/Desktop < 3.3.15'}, {'status': 'affected', 'version': 'Notesnook iOS/Android < 3.3.20'}]}] -
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
Jun. 17, 2026
Action Type Old Value New Value Added SSVC {'id': 'CVE-2026-42090', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'none'}, {'automatable': 'no'}, {'technicalImpact': 'total'}], 'version': '2.0.3', 'timestamp': '2026-05-04T00:00:00+00:00'} -
Initial Analysis by [email protected]
May. 12, 2026
Action Type Old Value New Value Added CPE Configuration OR *cpe:2.3:a:streetwriters:notesnook_desktop:*:*:*:*:*:*:*:* versions up to (excluding) 3.3.15 *cpe:2.3:a:streetwriters:notesnook_mobile:*:*:*:*:*:iphone_os:*:* versions up to (excluding) 3.3.20 *cpe:2.3:a:streetwriters:notesnook_mobile:*:*:*:*:*:android:*:* versions up to (excluding) 3.3.20 Added Reference Type GitHub, Inc.: https://github.com/streetwriters/notesnook/releases/tag/3.3.20-android Types: Release Notes Added Reference Type GitHub, Inc.: https://github.com/streetwriters/notesnook/releases/tag/v3.3.15 Types: Release Notes Added Reference Type GitHub, Inc.: https://github.com/streetwriters/notesnook/security/advisories/GHSA-fjm8-jg78-89h4 Types: Vendor Advisory -
New CVE Received by [email protected]
May. 04, 2026
Action Type Old Value New Value 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. Added CVSS V3.1 AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H Added CWE CWE-79 Added CWE CWE-94 Added Reference https://github.com/streetwriters/notesnook/releases/tag/3.3.20-android Added Reference https://github.com/streetwriters/notesnook/releases/tag/v3.3.15 Added Reference https://github.com/streetwriters/notesnook/security/advisories/GHSA-fjm8-jg78-89h4