CVE-2026-59209: n8n: Shared Credential Header Leak via HTTP Request Pagination Expression

An authenticated member with use-only editor access to a shared workflow could read credential-populated headers exposed via the $request object inside an HTTP Request node’s pagination expression. When an HTTP Header Auth credential is applied to a paginated request, the secret is present in $request.headers when pagination expressions are evaluated. A user-controlled expression could read that secret, copy it into item data, and exfiltrate it through a later HTTP Request node, bypassing credential domain restrictions, since the secret leaves via item data rather than the credential’s own request mechanism.

This issue only affects instances with N8N_EXPRESSION_ENGINE=vm set, where paginated HTTP Request workflows using shared credentials are accessible to non-owner users.