CVE-2026-73486

Flowise before 3.1.3 contains a code injection flaw (CWE-94) in the CSV Agent node's customReadCSV parameter, which authenticated attackers can abuse to run arbitrary Python code. The parameter is only validated by a static regex blocklist, which can be bypassed using obfuscation techniques, allowing injected code to run in the unsandboxed Pyodide environment with full system access. A successful attacker gains remote code execution on the Flowise host with high impact on confidentiality, integrity, and availability (CVSS 4.0 score 9, critical). Any deployment of Flowise prior to version 3.1.3 is affected, particularly instances where untrusted or low-privileged users can create or edit flows. No widespread in-the-wild exploitation is currently reported; a public advisory/PoC exists and EPSS places 30-day exploitation probability at about 0.7%.

What to do: Upgrade Flowise to version 3.1.3 or later, which fixes the CSV Agent customReadCSV validation bypass. In the meantime, restrict who can create or edit flows with the CSV Agent node, avoid untrusted input in customReadCSV, and limit network access to Flowise instances that must remain internet-exposed. Review instance logs for unexpected Python/Pyodide execution from authenticated users.