CVE-2026-31876 MEDIUM

CVE-2026-31876: Notesnook has Stored XSS via unsanitized Twitter/X embed URL in editor (`tweetToEmbed`)

Vendor Streetwriters
Product notesnook
Weakness CWE-79 · XSS
Published March 11, 2026
Last update March 12, 2026
View on NVD All CVEs

CVSS base score

5.4/10
Attack vector Network
Attack complexity Low
Privileges required Low
User interaction Required
Confidentiality Low
Integrity Low

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N

What the vulnerability does

01Description

Notesnook is a note-taking app focused on user privacy & ease of use. Prior to 3.3.9, a Stored Cross-Site Scripting (XSS) vulnerability existed in Notesnook's editor embed component when rendering Twitter/X embed URLs. The tweetToEmbed() function in component.tsx interpolated the user-supplied URL directly into an HTML string without escaping, which was then assigned to the srcdoc attribute of an <iframe>. This vulnerability is fixed in 3.3.9.

Key dates

02Disclosure timeline

March 11, 2026 CVE published
March 12, 2026 Record updated