Affected: Homebrew: mailcatcher

### Impact

If this library is used to implement a WebSocket server on top of a TCP server, by using the `WebSocket::Driver.server()` method, then a client can cause the server to crash by sending a `Host` header that is not a valid `host[:port]` string. When this happens, a `URI::InvalidURIError` exception is raised which is not caught, and this can cause the server process to crash if the application does not catch the error from the `parse()` method itself.

### Patches

The issue has been patched in version 0.8.2 by making the request parser catch `URI::InvalidURIError` and enter an error state if the `Host` header is malformed. This means the request is considered invalid and should not establish a WebSocket connection.

### Workarounds

No known workarounds exist.

### Acknowledgements

This issue was discovered and reported by Pranjali Thakur, DepthFirst Security Research Team.

websocket-driver is a WebSocket protocol handler with pluggable I/O. Prior to 0.8.2, WebSocket::Driver.server() passes a malformed Host header to URI.parse in lib/websocket/http/request.rb without catching URI::InvalidURIError, allowing a remote client to crash a TCP-backed WebSocket server when the application does not catch the error from parse(). This issue is fixed in version 0.8.2.

Affected: RubyGems: websocket-driver

### Impact

If this library is used to implement a WebSocket server on top of a TCP server, by using the `WebSocket::Driver.server()` method, then a client can cause the server to crash by sending a `Host` header that is not a valid `host[:port]` string. When this happens, a `URI::InvalidURIError` exception is raised which is not caught, and this can cause the server process to crash if the application does not catch the error from the `parse()` method itself.

### Patches

The issue has been patched in version 0.8.2 by making the request parser catch `URI::InvalidURIError` and enter an error state if the `Host` header is malformed. This means the request is considered invalid and should not establish a WebSocket connection.

### Workarounds

No known workarounds exist.

### Acknowledgements

This issue was discovered and reported by Pranjali Thakur, DepthFirst Security Research Team.

Affected: openEuler:20.03-LTS-SP4: rubygem-websocket-driver, openEuler:22.03-LTS-SP4: rubygem-websocket-driver, openEuler:24.03-LTS-SP1: rubygem-websocket-driver, openEuler:24.03-LTS-SP3: rubygem-websocket-driver, openEuler:24.03-LTS-SP4: rubygem-websocket-driver

This module provides a complete implementation of the WebSocket protocols that can be hooked up to any TCP library. It aims to simplify things by decoupling the protocol details from the I/O layer, such that users only need to implement code to stream data in and out of it without needing to know anything about how the protocol actually works. Think of it as a complete WebSocket system with pluggable I/O. Security Fix(es):

websocket-driver is a WebSocket protocol handler with pluggable I/O. Prior to 0.8.1, draft versions of the WebSocket protocol in websocket-driver include a length header that allows an arbitrarily large integer to be encoded as bytes with the high bit set, and a server or client can send an indefinite sequence of 0x80 or higher bytes that the peer parses into an ever-growing Ruby integer. This can make a WebSocket connection consume an unbounded amount of memory and lead to the host process running out of memory. This issue is fixed in version 0.8.1.(CVE-2026-54463)

### Impact

If this library is used in tandem with the `permessage-deflate` extension, a WebSocket server or client can be made to accept messages that are larger than the configured maximum message size. This is because this limit is checked against the message frames' length headers, which give the size of the compressed data, not the size after decompression. This can lead to applications accepting larger messages than expected and exceeding their intended resource usage.

### Patc…

Affected: Ubuntu:16.04:LTS: ruby-websocket-driver, Ubuntu:18.04:LTS: ruby-websocket-driver, Ubuntu:20.04:LTS: ruby-websocket-driver, Ubuntu:22.04:LTS: ruby-websocket-driver, Ubuntu:24.04:LTS: ruby-websocket-driver, Ubuntu:26.04:LTS: ruby-websocket-driver

websocket-driver is a WebSocket protocol handler with pluggable I/O. Prior to 0.8.2, WebSocket::Driver.server() passes a malformed Host header to URI.parse in lib/websocket/http/request.rb without catching URI::InvalidURIError, allowing a remote client to crash a TCP-backed WebSocket server when the application does not catch the error from parse(). This issue is fixed in version 0.8.2.