PT-2026-65898 · Rubygems · Mcp

CVE-2026-67431

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Published

2026-07-29

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Updated

2026-07-30

CVSS v4.0

8.3

High

VectorAV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:H/VA:L/SC:N/SI:N/SA:N
Name of the Vulnerable Software and Affected Versions mcp versions prior to 0.23.0
Description The MCP::Server::Transports::StreamableHTTPTransport component in the mcp gem fails to bind a session ID to a session owner. This allows an attacker who has obtained a stolen session ID to send tools/call requests that are executed within the context of the victim's session.
Recommendations Update to version 0.23.0.

Exploit

Fix

Improper Access Control

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Weakness Enumeration

CWE-284

Related Identifiers

CVE-2026-67431
GHSA-5P9G-J988-PCWV

Affected Products

Mcp