CVE-2026-35451CWE-79

Twenty: Stored XSS via BlockNote FileBlock

Medium · published April 21, 2026

CVSS v3.1
5.7
EPSS
0%
Percentile
35.4
In the wild
Unconfirmed
What it is

Twenty is an open source CRM. Prior to 1.20.6, a Stored Cross-Site Scripting (XSS) vulnerability exists in the BlockNote editor component. Due to a lack of protocol validation in the FileBlock component and insufficient server-side inspection of block content, an attacker can inject a javascript: URI into the url property of a file block. This allows the execution of arbitrary JavaScript when a user clicks on the malicious file attachment. This vulnerability is fixed in 1.20.6.

The record
Technical detail
CVSS v3.1
5.7 · MEDIUM
Vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:N/A:N
CVSS v4.0
Not supplied
EPSS
0.00421 · 35.4th percentile
Weakness
CWE-79 · Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
Published
2026-04-21T16:22Z
EPSS history
Timeline
  • 21 APR 16:22Z
    Twenty: Stored XSS via BlockNote FileBlock
    cvelistv5