CVE-2026-63119

MEDIUM
MEDIUM Priority: 0.01 BB Relevance: 47/100
Published: 2026-07-29 Modified: 2026-10-24 First seen: 2026-10-29 Status: active

Attack Surface

Low Complexity No Auth No Interaction

CVSS Vector Breakdown

AV: Local
AC: Low
PR: None
UI: None
S: Unchanged
C: None
I: None
A: High

Description

MCP Ruby SDK is the official Ruby SDK for Model Context Protocol servers and clients. Prior to 0.23.0, MCP::Server::Transports::StdioTransport and MCP::Client::Stdio in the mcp gem use IO#gets without a byte limit, allowing a peer that sends data without a newline to exhaust process memory. This issue is fixed in version 0.23.0.

Weakness Classification (2)

Bug Bounty Relevance

47 / 100
✓ No authentication
✓ Low complexity
✓ No user interaction

CVSS Score

6.2 / 10.0 v3.1
CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

EPSS — Exploitation Probability

0.19%
Raw Score 0.001880
Percentile 8.4%
Date 2026-10-29

EPSS Trend

2026-10-29
0.00188
2026-10-28
0.00188

Intelligence Sources

nvd ref →