CVE-2025-46343: 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
- n8n@1.90.0
Credit We would like to thank @Mahmoud0x00 for reporting this issue.
Other sources
n8n is a workflow automation platform. Prior to version 1.90.0, n8n is vulnerable to stored cross-site scripting (XSS) through the attachments view endpoint. n8n workflows can store and serve binary files, which are accessible to authenticated users. However, there is no restriction on the MIME type of uploaded files, and the MIME type could be controlled via a GET parameter. This allows 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 send a request to change the user’s email address in their account settings, effectively enabling account takeover. This issue has been patched in version 1.90.0.
— MITRE
Affected Software
Remediation
Patch Available
Patch Available
Event History
Frequently Asked Questions
What is the severity of CVE-2025-46343?
The severity of CVE-2025-46343 is considered medium due to the potential for unauthorized access to sensitive files via manipulated MIME types.
How do I fix CVE-2025-46343?
To fix CVE-2025-46343, upgrade n8n to version 1.90.0 or later to ensure proper restrictions on MIME types.
Who is affected by CVE-2025-46343?
Users of n8n versions prior to 1.90.0 are affected by CVE-2025-46343 due to the lack of MIME type restrictions.
What is the impact of CVE-2025-46343?
The impact of CVE-2025-46343 includes the risk of serving and accessing malicious files due to uncontrolled MIME type management.
What type of vulnerability is CVE-2025-46343?
CVE-2025-46343 is classified as a vulnerability that allows MIME type confusion, posing security risks through file uploads.