Transmission 4.0.0 before 4.1.3 contains a permissive CORS vulnerability in handle_request() in rpc-server.cc that exposes the X-Transmission-Session-Id anti-CSRF token to any web origin.
CVSS 4.0HIGH 8.7·Network·No auth·User interaction·EPSS 0.01246·Published 2026-10-26·Fixed in 4.1.3CWE-942