Notesnook: RCE via stored XSS in note export rendering
Summary
| CVE | CVE-2026-42090 |
|---|---|
| State | PUBLISHED |
| Assigner | GitHub_M |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-05-04 17:16:25 UTC |
| Updated | 2026-05-12 18:45:43 UTC |
| 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. |
Risk And Classification
Primary CVSS: v3.1 9.6 CRITICAL from [email protected]
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H
EPSS: 0.001710000 probability, percentile 0.379030000 (date 2026-05-12)
Problem Types: CWE-79 | CWE-94 | CWE-79 CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') | CWE-94 CWE-94: Improper Control of Generation of Code ('Code Injection')
| Version | Source | Type | Score | Severity | Vector |
|---|---|---|---|---|---|
| 3.1 | [email protected] | Secondary | 9.6 | CRITICAL | CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H |
| 3.1 | CNA | DECLARED | 9.6 | CRITICAL | CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H |
CVSS v3.1 Breakdown
Attack Vector
NetworkAttack Complexity
LowPrivileges Required
NoneUser Interaction
RequiredScope
ChangedConfidentiality
HighIntegrity
HighAvailability
HighCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H
NVD Known Affected Configurations (CPE 2.3)
| Type | Vendor | Product | Version | Update | Edition | Language |
|---|---|---|---|---|---|---|
| Application | Streetwriters | Notesnook Desktop | All | All | All | All |
| Application | Streetwriters | Notesnook Mobile | All | All | All | All |
| Application | Streetwriters | Notesnook Mobile | All | All | All | All |
Vendor Declared Affected Products
| Source | Vendor | Product | Version | Platforms |
|---|---|---|---|---|
| CNA | Streetwriters | Notesnook | affected Notesnook Web/Desktop < 3.3.15 | Not specified |
| CNA | Streetwriters | Notesnook | affected Notesnook iOS/Android < 3.3.20 | Not specified |
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| github.com/streetwriters/notesnook/releases/tag/v3.3.15 | [email protected] | github.com | Release Notes |
| github.com/streetwriters/notesnook/security/advisories/GHSA-fjm8-jg78-89h4 | [email protected] | github.com | Vendor Advisory |
| github.com/streetwriters/notesnook/releases/tag/3.3.20-android | [email protected] | github.com | Release Notes |
| CVE Program record | CVE.ORG | www.cve.org | canonical |
| NVD vulnerability detail | NVD | nvd.nist.gov | canonical, analysis |
No vendor comments have been submitted for this CVE.
There are currently no legacy QID mappings associated with this CVE.