Session Hijacking

MCP Ruby SDK is vulnerable to Session Hijacking. The vulnerability is due to insufficient session binding, where an attacker who obtains a valid session ID can completely hijack the victim's Server-Sent Events SSE stream and intercept all real-time data...

Session Fixation

Overview mcp is a The official Ruby SDK for Model Context Protocol servers and clients Affected versions of this package are vulnerable to Session Fixation through the storestreamforsession process in lib/mcp/server/transports/streamablehttptransport.rb. An attacker can intercept all subsequent...

CVE-2026-33946

MCP Ruby SDK is the official Ruby SDK for Model Context Protocol servers and clients. Prior to version 0.9.2, the Ruby SDK's streamablehttptransport.rb implementation contains a session hijacking vulnerability. An attacker who obtains a valid session ID can completely hijack the victim's...

CVE-2026-33946 MCP Ruby SDK: Insufficient Session Binding Allows SSE Stream Hijacking via Session ID Replay

MCP Ruby SDK is the official Ruby SDK for Model Context Protocol servers and clients. Prior to version 0.9.2, the Ruby SDK's streamablehttptransport.rb implementation contains a session hijacking vulnerability. An attacker who obtains a valid session ID can completely hijack the victim's...

EUVD-2026-16866

MCP Ruby SDK is the official Ruby SDK for Model Context Protocol servers and clients. Prior to version 0.9.2, the Ruby SDK's streamablehttptransport.rb implementation contains a session hijacking vulnerability. An attacker who obtains a valid session ID can completely hijack the victim's...

CVE-2026-33946

MCP Ruby SDK is the official Ruby SDK for Model Context Protocol servers and clients. Prior to version 0.9.2, the Ruby SDK's streamablehttptransport.rb implementation contains a session hijacking vulnerability. An attacker who obtains a valid session ID can completely hijack the victim's...

CVE-2026-33946

The CVE affects the MCP Ruby SDK prior to 0.9.2. In streamable_http_transport.rb, an attacker with a valid session ID can hijack the victim’s SSE stream and intercept real-time data, due to insufficient session binding. Version 0.9.2 patches this. No additional exploit details are provided beyond...

CVE-2026-31950 LibreChat's IDOR in SSE Stream Subscription Allows Reading Other Users' Chats

LibreChat is a ChatGPT clone with additional features. In versions 0.8.2-rc2 through 0.8.2-rc3, the SSE streaming endpoint /api/agents/chat/stream/:streamId does not verify that the requesting user owns the stream. Any authenticated user who obtains or guesses a valid stream ID can subscribe and...

MCP Ruby SDK: Insufficient Session Binding Allows SSE Stream Hijacking via Session ID Replay

Summary The Ruby SDK's streamablehttptransport.rb implementation contains a session hijacking vulnerability. An attacker who obtains a valid session ID can completely hijack the victim's Server-Sent Events SSE stream and intercept all real-time data. Details Root Cause The StreamableHTTPTransport...

MCP Ruby SDK - Insufficient Session Binding Allows SSE Stream Hijacking via Session ID Replay

Summary The Ruby SDK's streamablehttptransport.rb implementation contains a session hijacking vulnerability. An attacker who obtains a valid session ID can completely hijack the victim's Server-Sent Events SSE stream and intercept all real-time data. Details Root Cause The StreamableHTTPTransport...

PT-2026-28576

Name of the Vulnerable Software and Affected Versions MCP Ruby SDK versions prior to 0.9.2 Description The Ruby SDK for Model Context Protocol servers and clients contains a session hijacking issue in its streamable http transport.rb implementation. An attacker obtaining a valid session ID can...

PT-2026-28431

Name of the Vulnerable Software and Affected Versions LibreChat versions 0.8.2-rc2 through 0.8.2-rc3 Description LibreChat, a ChatGPT clone, has an issue where the SSE streaming endpoint /api/agents/chat/stream/:streamId does not confirm that the user making the request is authorized to access th...

LibreChat 访问控制错误漏洞

LibreChat is an open-source, free, and highly customizable unified AI conversation platform. It allows for the aggregation and running of large models from any vendor within one interface. Versions of LibreChat 0.8.2-rc2 to 0.8.2-rc3 contain an access control vulnerability. This vulnerability ste...

CVE-2026-31882

Dagu is a workflow engine with a built-in Web user interface. Prior to 2.2.4, when Dagu is configured with HTTP Basic authentication DAGUAUTHMODE=basic, all Server-Sent Events SSE endpoints are accessible without any credentials. This allows unauthenticated attackers to access real-time DAG...

CRLF Injection

Overview org.webjars.npm:h3 is a Minimal HTTP framework built for high performance and portability. Affected versions of this package are vulnerable to CRLF Injection via unsanitized carriage return characters in the data and comment fields of the EventStream class. An attacker can inject arbitra...

h3: SSE Event Injection via Unsanitized Carriage Return (`\r`) in EventStream Data and Comment Fields (Bypass of CVE Fix)

Summary The EventStream class in h3 fails to sanitize carriage return \r characters in data and comment fields. Per the SSE specification, \r is a valid line terminator, so browsers interpret injected \r as line breaks. This allows an attacker to inject arbitrary SSE events, spoof event types, an...

GHSA-4HXC-9384-M385 h3: SSE Event Injection via Unsanitized Carriage Return (`\r`) in EventStream Data and Comment Fields (Bypass of CVE Fix)

Summary The EventStream class in h3 fails to sanitize carriage return \r characters in data and comment fields. Per the SSE specification, \r is a valid line terminator, so browsers interpret injected \r as line breaks. This allows an attacker to inject arbitrary SSE events, spoof event types, an...

CVE-2026-33128

A flaw was found in H3, a minimal HTTP framework. A remote attacker can exploit this flaw by injecting malicious Server-Sent Events SSE due to improper sanitization of newline characters in the formatEventStreamMessage and formatEventStreamComment functions. An attacker who controls any part of a...

CVE-2026-33128

H3 is a minimal HTTP framework. In versions prior to 1.15.6 and between 2.0.0 through 2.0.1-rc.14, createEventStream is vulnerable to Server-Sent Events SSE injection due to missing newline sanitization in formatEventStreamMessage and formatEventStreamComment. An attacker who controls any part of...

CVE-2026-33128 h3 has a Server-Sent Events Injection via Unsanitized Newlines in Event Stream Fields

H3 is a minimal HTTP framework. In versions prior to 1.15.6 and between 2.0.0 through 2.0.1-rc.14, createEventStream is vulnerable to Server-Sent Events SSE injection due to missing newline sanitization in formatEventStreamMessage and formatEventStreamComment. An attacker who controls any part of...