PT-2026-34007 · Blocknote · Blocknote

Published 2026-04-21 · Updated 2026-04-21 · CVE-2026-35451

Positive Technologies (AI Summary)

CVSS v3.1

5.7

Medium

Base vector

AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:N/A:N

Name of the Vulnerable Software and Affected Versions Twenty versions prior to 1.20.6

Description A Stored Cross-Site Scripting (XSS) issue 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.

Recommendations Update to version 1.20.6.

Exploit

Fix

XSS

Weakness Enumeration

CWE-79

Related Identifiers

CVE-2026-35451

Affected Products

Blocknote

References · 5

• 🔥 https://github.com/twentyhq/twenty/security/advisories/GHSA-7w89-7q26-gj7q · Exploit
• https://nvd.nist.gov/vuln/detail/CVE-2026-35451 · Security Note
• https://github.com/twentyhq/twenty/commit/8da69e0f77ea820a6845a4c3c025b6af3861d523 · Note
• https://twitter.com/infoflowcloud/status/2046637532230606990 · Twitter Post
• https://twitter.com/CVEnew/status/2046636246370300324 · Twitter Post