n8n before 1.123.69, 2.x before 2.33.4, and 2.34.x before 2.34.1 contain an expression injection vulnerability in resource-locator field link preview rendering. The editor spliced the field's stored value directly into the node type's URL template without checking for expression syntax. An authenticated member can store a malicious value so that when another user opens the affected node in the editor, the injected expression is evaluated as JavaScript in the victim's authenticated session (cross-user script execution).