CVE-2026-42090
9.6 · CRITICALOverview
CVE-2026-42090 is a critical-severity vulnerability affecting streetwriters notesnook_desktop. It was published on May 4, 2026 and has a CVSS 3.1 base score of 9.6 (CRITICAL).
This vulnerability has a CVSS 3.1 base score of 9.6, rated CRITICAL. It can be exploited remotely over the network. No authentication or special privileges are required for exploitation.
Technical 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
Check the references section for vendor advisories and patches from streetwriters. Update notesnook_desktop to the latest patched version. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.
Affected Products
| Vendor | Product | Versions | Status |
|---|---|---|---|
| streetwriters | notesnook_desktop | >= 0, < 3.3.15 | Affected |
| streetwriters | notesnook_mobile | >= 0, < 3.3.20 | Affected |
Frequently Asked Questions
What is CVE-2026-42090?
CVE-2026-42090 is a critical-severity vulnerability affecting streetwriters notesnook_desktop. It was published on May 4, 2026 and has a CVSS 3.1 base score of 9.6 (CRITICAL).
How severe is CVE-2026-42090?
This vulnerability has a CVSS 3.1 base score of 9.6, rated CRITICAL. It can be exploited remotely over the network. No authentication or special privileges are required for exploitation.
How do I fix or remediate CVE-2026-42090?
Check the references section for vendor advisories and patches from streetwriters. Update notesnook_desktop to the latest patched version. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.
How can CyberStrike help with CVE-2026-42090?
CyberStrike's AI-powered security agents can automatically detect CVE-2026-42090 across your infrastructure using autonomous pentesting, DAST scanning, and HackBrowser. The platform continuously monitors for known vulnerabilities and provides actionable remediation guidance prioritized by real-world exploitability.
How CyberStrike Helps
AI agents map your attack surface to find vulnerabilities like this one.
Automated penetration testing that runs continuously, not just quarterly.
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Browser-based exploitation validates findings with real proof-of-concept.
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