CVE-2026-110847: n8n before 1.123.83, 2.41.4, and 2.42.1 Stored XSS via Chat Trigger customCss Parameter
n8n before 1.123.83, 2.x before 2.41.4, and 2.42.x before 2.42.1 contains a stored cross-site scripting vulnerability in the Chat Trigger hosted-chat page, where insufficiently sanitised customCss values are interpolated into the page as markup. Workflow authors can publish a chat without n8n user authentication whose payload executes on the instance origin, acting on the sessions of signed-in visitors.
Affected Software
Event History
Frequently Asked Questions
Which users are at risk from a malicious workflow?
Signed-in visitors to the n8n instance are at risk if they visit a published hosted-chat page containing a malicious customCss payload. The payload executes on the n8n instance origin and can act in the context of their sessions.
What access does an attacker need to exploit this issue?
The attacker needs the ability to author and publish a workflow using the Chat Trigger hosted-chat page and set its customCss value. The published chat can be accessible without n8n user authentication.
Which installations should be considered affected?
Affected releases are n8n versions before 1.123.83, 2.x versions before 2.41.4, and 2.42.x versions before 2.42.1. Review published Chat Trigger workflows on instances running those versions.
What should be reviewed while an upgrade is pending?
Review published hosted-chat workflows, especially any that use the Chat Trigger customCss parameter, and identify workflows created by untrusted or insufficiently trusted authors. Published unauthenticated chat pages are the relevant exposure path described for this issue.