n8n Vulnerable to Stored XSS through Attachments View Endpoint
Impact
n8n workflows can store and serve binary files, which are accessible to authenticated users. However, there was no restriction on the MIME type of uploaded files, and the MIME type could be controlled via a GET parameter. This allowed the server to respond with any MIME type, potentially enabling malicious content to be interpreted and executed by the browser.
An authenticated attacker with member-level permissions could exploit this by uploading a crafted HTML file containing malicious JavaScript. When another user visits the binary data endpoint with the MIME type set to text/html, the script executes in the context of the user’s session. This script could, for example, send a request to change the user’s email address in their account settings, effectively enabling account takeover.
Patches
Credit
We would like to thank @Mahmoud0x00 for reporting this issue.
Affected software
Click a technology to see all vulnerabilities affecting it.
| Platform | Package | Vulnerable versions | Fixed in |
|---|---|---|---|
| npm package | n8n | < 1.90.0 | 1.90.0 |
References
- CVSS vector
CVSS:3.1/AV:L/AC:H/PR:L/UI:R/S:U/C:H/I:L/A:N- Weakness (CWE)
CWE-79- Platform
- npm
- Package
n8n- Disclosed
- 28.04.2025
- Updated
- 11.10.2026 10:22
Sources and licenses
OSV / GitHub Advisory Database - GHSA-c8hm-hr8h-5xjw - CC BY 4.0
Vulnerability history: n8n
All published vulnerabilities of this package (npm package), newest first. Shows whether this is a one-off slip or a package that needs watching.
- Total entries
- 156
- First → latest
- 05.2023 09.2026
- Without a fix
- 1
- Exploited in attacks
- 1
Severity breakdown
- Critical 24
- High 58
- Medium 74
Disclosures per year
- 2023: 3
- 2024: 0
- 2025: 14
- 2026: 139
-
n8n Vulnerable to Stored XSS through Attachments View Endpoint this entry
Know which vulnerabilities affect your application
With the DockRay integration and software inventory enabled, DockRay checks reported component versions against known vulnerabilities and notifies you about confirmed matches. Coverage depends on the supported technology and available advisory data.