fix case 5.18

Author: KhafraDev

lib/web/websocket/receiver.js

@@ -12,7 +12,8 @@ const {
   websocketMessageReceived,
   utf8Decode,
   isControlFrame,
-  isContinuationFrame
+  isContinuationFrame,
+  isTextBinaryFrame
 } = require('./util')
 const { WebsocketFrameSend } = require('./frame')
 const { CloseEvent } = require('./events')
@@ -92,12 +93,19 @@ class ByteParser extends Writable {
 
         const fragmented = !fin && opcode !== opcodes.CONTINUATION
 
-        if (fragmented && opcode !== opcodes.BINARY && opcode !== opcodes.TEXT) {
+        if (fragmented && !isTextBinaryFrame(opcode)) {
           // Only text and binary frames can be fragmented
           failWebsocketConnection(this.ws, 'Invalid frame type was fragmented.')
           return
         }
 
+        // If we are already parsing a text/binary frame and do not receive either
+        // a continuation frame or close frame, fail the connection.
+        if (isTextBinaryFrame(opcode) && this.#info.opcode !== undefined) {
+          failWebsocketConnection(this.ws, 'Expected continuation frame')
+          return
+        }
+
         const payloadLength = buffer[1] & 0x7F
 
         if (isControlFrame(opcode)) {