FKIE_CVE-2026-33946

Vulnerability from fkie_nvd - Published: 2026-03-27 22:16 - Updated: 2026-04-02 15:23
Severity ?
5.9 (Medium) - CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N
Summary
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 streamable_http_transport.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. Version 0.9.2 contains a patch.
References
security-advisories@github.comhttps://github.com/modelcontextprotocol/csharp-sdk/blob/main/src/ModelContextProtocol.AspNetCore/SseHandler.cs#L93-L97Patch
security-advisories@github.comhttps://github.com/modelcontextprotocol/go-sdk/blob/main/mcp/streamable.go#L281C1-L288C2Patch
security-advisories@github.comhttps://github.com/modelcontextprotocol/python-sdk/blob/main/src/mcp/server/streamable_http.py#L680-L685Patch
security-advisories@github.comhttps://github.com/modelcontextprotocol/ruby-sdk/blob/main/examples/streamable_http_server.rbPatch
security-advisories@github.comhttps://github.com/modelcontextprotocol/ruby-sdk/commit/db40143402d65b4fb6923cec42d2d72cb89b3874Patch
security-advisories@github.comhttps://github.com/modelcontextprotocol/ruby-sdk/releases/tag/v0.9.2Product, Release Notes
security-advisories@github.comhttps://github.com/modelcontextprotocol/ruby-sdk/security/advisories/GHSA-qvqr-5cv7-wh35Exploit, Vendor Advisory
security-advisories@github.comhttps://hackerone.com/reports/3556146Permissions Required
134c704f-9b21-4f2e-91b3-4a467353bcc0https://github.com/modelcontextprotocol/ruby-sdk/security/advisories/GHSA-qvqr-5cv7-wh35Exploit, Vendor Advisory
Impacted products
Vendor Product Version
lfprojects mcp_ruby_sdk *
To clipboard 

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