[2624:2624:0527/170756.193123:ERROR:third_party/blink/renderer/platform/loader/fetch/url_loader/request_conversion.cc:454] [POC renderer] injected X-HTTP-Method-Override: TRACE on http://127.0.0.1:18081/reflect?poc-method-override (mode=1, credentials_mode=2)
[2526:2526:0527/170756.227818:INFO:CONSOLE:10] "[POC] attacker origin: http://127.0.0.1:18080", source: http://127.0.0.1:18080/poc.html (10)
[2526:2526:0527/170756.227893:INFO:CONSOLE:10] "[POC] victim   origin: http://127.0.0.1:18081", source: http://127.0.0.1:18080/poc.html (10)
[2526:2526:0527/170756.228019:INFO:CONSOLE:10] "[POC] fetch("http://127.0.0.1:18081/reflect?poc-method-override", {method:"POST", mode:"no-cors", credentials:"include"})", source: http://127.0.0.1:18080/poc.html (10)
[2526:2526:0527/170756.265398:INFO:CONSOLE:10] "[POC] ERROR: TypeError: Failed to fetch", source: http://127.0.0.1:18080/poc.html (10)

=== server log (with fix) ===
[*] attacker origin: http://127.0.0.1:18080
[*] victim   origin: http://127.0.0.1:18081
[*] entry point:     http://127.0.0.1:18081/setcookie
[victim:18081] "GET /setcookie HTTP/1.1" 302 -
[attacker:18080] "GET /poc.html HTTP/1.1" 200 -
[attacker:18080] code 404, message File not found
[attacker:18080] "GET /favicon.ico HTTP/1.1" 404 -