Vulnerability · Published Mar 11, 2026 · Assigned by GitHub_M

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

Medium 5.4

In plain English

A medium-severity cross-site scripting in notesnook from streetwriters. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 11% of all known vulnerabilities).

Severity (CVSS 3.1)5.4Medium

Exploit odds (30 days)0.2%top 89.5% of all CVEs

Exploited in the wildNo reportsCISA SSVC: none

Attack toolingNoneno public tooling known

Official description

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.

Affected products (as reported)

Vendor	Product	Versions
streetwriters	notesnook	< 3.3.9

Weakness: CWE-79 · Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N

References

https://github.com/streetwriters/notesnook/security/advisories/GHSA-jprx-2w2h-4rh5 x_refsource_CONFIRM
https://github.com/streetwriters/notesnook/commit/e87f5e5f899f45df28d7c0f33f15e9178d1fbcb7 x_refsource_MISC