RCE in Streetwriters Notesnook

CVE-2026-42090

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 r…

Vulnerability class: XSS (Cross-Site Scripting)

EPSS: 0.002 (38.1th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 9.6 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H.

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-42090?
CVE-2026-42090 is a critical-severity vulnerability in Streetwriters Notesnook, classified under Cross-site Scripting. CVSS score: 9.6/10. Published 2026-05-04.
How severe is CVE-2026-42090?
Critical severity. CVSS v3 base score is 9.6 out of 10.