Dashboard / CVE-2026-63118

CVE-2026-63118

MEDIUM
MEDIUM Priority: 0.02 BB Relevance: 64/100
Published: 2026-07-29 Modified: 2026-10-24 First seen: 2026-10-29 Status: active

Attack Surface

Network Low Complexity No Auth Conf. Impact

CVSS Vector Breakdown

AV: Network
AC: Low
PR: None
UI: Active
S: X
AT: Present
VC: High
VI: None
VA: None

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 validate the HTTP Host or Origin request headers, which allows a malicious browser page to use DNS rebinding to reach a locally running MCP server and invoke exposed tools. This issue is fixed in version 0.23.0.

Weakness Classification (2)

References & Advisories (3)

Bug Bounty Relevance

64 / 100
✓ Network accessible
✓ No authentication
✓ Low complexity

CVSS Score

6.9 / 10.0 v4.0
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:A/VC:H/VI:N/VA:N/SC:H/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

EPSS — Exploitation Probability

0.24%
Raw Score 0.002390
Percentile 15.0%
Date 2026-10-29

EPSS Trend

2026-10-29
0.00239
2026-10-28
0.00239

Intelligence Sources

nvd ref →

External Links