Flowise System Message Override via Template Interpolation (CVE-2025-59528) - ATR-2026-00210 (c62f61b6-7aa4-5fc2-b6f3-ec8f6e3e5c9f)
Detects exploitation of the Flowise chatflow System Message template injection vulnerability (CVE-2025-59528). Flowise renders {{$flow.variables.X}} and {{$input}} in the System Message field without sanitization, allowing an attacker-controlled chat input to overwrite the system prompt and pivot the chatflow's tool-calling posture. Public PoCs achieved RCE via the vm.runInNewContext / new Function sink reached from a polluted System Message. 21 GHSAs published 2026-04-15 cover the affected chatflow surfaces (Airtable Agent, CSV Agent, Parameter Override, etc.). Disclosed 2026-04-14.