CVE-2026-67431

MCP Ruby SDK is the official Ruby SDK for Model Context Protocol servers and clients. Prior to 0.23.0, MCP::Server::Transports::StreamableHTTPTransport in the mcp gem does not bind a session ID to a session owner, allowing an attacker with a stolen session ID to send tools/call requests that execute in the victim's session. This issue is fixed in version 0.23.0.

CVSS

No CVSS.

References

Link	Resource
https://github.com/modelcontextprotocol/ruby-sdk/commit/35466605319a34e4c7808712ae9bb1ca1afb2356
https://github.com/modelcontextprotocol/ruby-sdk/releases/tag/v0.23.0
https://github.com/modelcontextprotocol/ruby-sdk/security/advisories/GHSA-5p9g-j988-pcwv
https://github.com/modelcontextprotocol/ruby-sdk/security/advisories/GHSA-5p9g-j988-pcwv

Configurations

No configuration.

History

No history.

Information

Published : 2026-07-29 20:17

Updated : 2026-07-30 19:30

NVD link : CVE-2026-67431

Mitre link : CVE-2026-67431

CVE.ORG link : CVE-2026-67431

JSON object : View

Products Affected

No product.

CWE

CWE-284

Improper Access Control

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