CVE-2026-67431EPSS p39.3%

CVE-2026-67431CVE-2026-67431

Description

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.

Scoring

EPSS0.48% probability of exploitation · percentile 39.3% · 2026-10-05T12:00:23Z
Last modified2026-07-30
Sourced from NVD + FIRST.org EPSS. Curated for EU compliance use cases by Adam Lundqvist, Founder at SQUR.