diff --git a/middleware/cors.go b/middleware/cors.go
index 9f40e9f0..0181d270 100644
--- a/middleware/cors.go
+++ b/middleware/cors.go
@@ -489,6 +489,21 @@ func validateAllowCredentials(
 		return errors.New("ong/middleware/cors: allowCredentials should not be used together with wildcard allowedHeaders")
 	}
 
+	if allowCredentials {
+		// Credentialed requests should not be used with 'http' scheme. Should require 'https'.
+		// https://jub0bs.com/posts/2023-02-08-fearless-cors/#disallow-insecure-origins-by-default
+		// https://portswigger.net/research/exploiting-cors-misconfigurations-for-bitcoins-and-bounties
+		for _, origin := range allowedOrigins {
+			u, err := url.Parse(origin)
+			if err != nil {
+				return err
+			}
+			if u.Scheme == "http" {
+				return fmt.Errorf("ong/middleware/cors: allowCredentials should not be used together with origin that uses unsecure scheme `%v`", origin)
+			}
+		}
+	}
+
 	return nil
 }
 
diff --git a/middleware/cors_test.go b/middleware/cors_test.go
index 42a0ccc7..826c5169 100644
--- a/middleware/cors_test.go
+++ b/middleware/cors_test.go
@@ -930,7 +930,7 @@ func TestValidateAllowCredentials(t *testing.T) {
 		{
 			name:             "credentials no wildcard origin",
 			allowCredentials: true,
-			allowedOrigins:   []string{"http://example.com"},
+			allowedOrigins:   []string{"https://example.com"},
 			allowedMethods:   nil,
 			allowedHeaders:   nil,
 			succeeds:         true,
@@ -954,6 +954,15 @@ func TestValidateAllowCredentials(t *testing.T) {
 			succeeds:         false,
 			errMsg:           "allowCredentials should not be used together with wildcard",
 		},
+		{
+			name:             "insecure http scheme",
+			allowCredentials: true,
+			allowedOrigins:   []string{"http://example.org"},
+			allowedMethods:   nil,
+			allowedHeaders:   nil,
+			succeeds:         false,
+			errMsg:           "allowCredentials should not be used together with origin that uses unsecure scheme",
+		},
 	}
 
 	for _, tt := range tests {