CVE-2026-43678

An unauthenticated remote peer can crash any NIOWebSocket-based server including Vapor and Hummingbird with a single 11-byte frame sent after a completed WebSocket handshake, dropping all active connections until the process restarts. This vulnerability is addressed in swift-nio version 2.101.0...

CVE-2026-73565

CVE-2026-73565 affects @hono/node-server

CVE-2026-73565 @hono/node-server: Unauthenticated memory-leak DoS via aborted WebSocket handshake

@hono/node-server allows running the Hono application on Node.js. From 2.0.0 until 2.0.10, a WebSocket upgrade request to an upgradeWebSocket route with a missing or malformed Sec-WebSocket-Key header causes src/websocket.ts to retain the request's IncomingMessage in waiterMap and leave...

CVE-2026-73565 @hono/node-server: Unauthenticated memory-leak DoS via aborted WebSocket handshake

@hono/node-server allows running the Hono application on Node.js. From 2.0.0 until 2.0.10, a WebSocket upgrade request to an upgradeWebSocket route with a missing or malformed Sec-WebSocket-Key header causes src/websocket.ts to retain the request's IncomingMessage in waiterMap and leave...

io.netty/netty-codec-http: Netty: Protocol version confusion in netty-codec-http (WebSocket)

A flaw was found in netty-codec-http. The WebSocket handshaker in this component fails to properly validate protocol version information during the WebSocket upgrade process. A remote attacker can exploit this vulnerability by manipulating the WebSocket handshake, leading to a bypass of security...

CVE-2026-59898

A flaw was found in netty-codec-http. The WebSocket handshaker in this component fails to properly validate protocol version information during the WebSocket upgrade process. A remote attacker can exploit this vulnerability by manipulating the WebSocket handshake, leading to a bypass of security...

HTTP Request Smuggling

io.netty, netty-codec-http is vulnerable to HTTP Request Smuggling. The vulnerability is due to the WebSocket V07/V08 handshaker accepting a WebSocket upgrade request without requiring the Connection: Upgrade and Upgrade: websocket headers, which allows an attacker to force an unrecognized protoc...

HTTP Request Smuggling

Overview io.netty:netty-codec-http is a network application framework for rapid development of maintainable high performance protocol servers & clients. Affected versions of this package are vulnerable to HTTP Request Smuggling in the WebSocket handshake. An attacker can bypass expected header...

Denial Of Service (DoS)

websocket-driver is vulnerable to Denial Of Service DoS. The vulnerability is due to the lack of limits on processing HTTP request or response headers during the WebSocket handshake, which allows an attacker to send an endless list of headers and exhaust the receiving process's memory, resulting ...

Improper Origin Validation

MCP Python SDK is vulnerable to Improper Origin Validation. The vulnerability is due to the WebSocket transport accepting handshake requests without validating the Host or Origin headers, which allows an attacker to establish unauthorized cross-origin WebSocket connections...

CVE-2026-55517

Deno is a JavaScript, TypeScript, and WebAssembly runtime. Prior to 2.7.5, a Deno program that opens a client WebSocket connection could be crashed by the remote server. While handling the WebSocket handshake response, Deno parsed the Sec-WebSocket-Protocol and Sec-WebSocket-Extensions response...

CVE-2026-55517

CVE-2026-55517 affects Deno prior to 2.7.5, where a client WebSocket handshake could crash the process if the server returned non-ASCII bytes in Sec-WebSocket-Protocol or Sec-WebSocket-Extensions headers. The root cause is parsing those headers as ASCII strings, triggering a panic when non-printa...

Deno: Denial of service via non-ASCII bytes in WebSocket response headers

Summary A Deno program that opens a client WebSocket connection could be crashed by the remote server. While handling the WebSocket handshake response, Deno parsed the Sec-WebSocket-Protocol and Sec-WebSocket-Extensions response headers in a way that assumed their bytes were always printable ASCI...

CVE-2026-45541 ESF-IDF: Remote Null Pointer Dereference in WebSocket Server

ESF-IDF is the Espressif Internet of Things IOT Development Framework. In versions 5.2.6, 5.3.5, 5.4.4, 5.5.4, and 6.0, a NULL-pointer dereference exists in the WebSocket subprotocol-negotiation path of the esphttpserver component. While parsing the client-supplied Sec-WebSocket-Protocol request...

CVE-2026-45541

The CVE describes a NULL-pointer dereference in the WebSocket subprotocol-negotiation path of the esp_http_server component in ESF-IDF. During the WebSocket handshake, parsing the clientS WebSocket Protocol header may dereference a NULL tokenisation result, causing a crash before any application...

CVE-2026-45541 ESF-IDF: Remote Null Pointer Dereference in WebSocket Server

ESF-IDF is the Espressif Internet of Things IOT Development Framework. In versions 5.2.6, 5.3.5, 5.4.4, 5.5.4, and 6.0, a NULL-pointer dereference exists in the WebSocket subprotocol-negotiation path of the esphttpserver component. While parsing the client-supplied Sec-WebSocket-Protocol request...

EUVD-2026-35914

ESF-IDF is the Espressif Internet of Things IOT Development Framework. In versions 5.2.6, 5.3.5, 5.4.4, 5.5.4, and 6.0, a NULL-pointer dereference exists in the WebSocket subprotocol-negotiation path of the esphttpserver component. While parsing the client-supplied Sec-WebSocket-Protocol request...

GHSA-XH68-HFP5-5X5M daphne: WebSocket handshake header smuggling through autobahn splitlines() mishandling of non-standard line separators

daphne before 4.2.2 reconstructs a raw HTTP request from Twisted's parsed headers and feeds it to autobahn for WebSocket handshake processing. Twisted does not treat \x0b, \x0c, \x1c, \x1d, \x1e, or \x85 as header line separators, but autobahn decodes header values to str and calls splitlines. An...

CVE-2026-44546

daphne before 4.2.2 reconstructs a raw HTTP request from Twisted's parsed headers and feeds it to autobahn for WebSocket handshake processing. Twisted does not treat \x0b, \x0c, \x1c, \x1d, \x1e, or \x85 as header line separators, but autobahn decodes header values to str and calls splitlines. An...

PYSEC-0000-CVE-2026-44546

daphne before 4.2.2 reconstructs a raw HTTP request from Twisted's parsed headers and feeds it to autobahn for WebSocket handshake processing. Twisted does not treat \x0b, \x0c, \x1c, \x1d, \x1e, or \x85 as header line separators, but autobahn decodes header values to str and calls splitlines. An...