ShellCodeX vulnerability brief
MEDIUM
Received
CVE-2026-63118
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.
Published 29 Jul 2026, 20:17 UTC
Last modified 29 Jul 2026, 20:17 UTC
01
Attack profile
The conditions required to exploit this vulnerability and its potential impact.
Attack vector
Network
Attack complexity
Low
Privileges required
None
User interaction
Active
Scope
Not assessed
Confidentiality
Not assessed
Integrity
Not assessed
Availability
Not assessed
02
Affected products
Product applicability statements supplied with the NVD record.
NVD has not published structured affected-product data for this record.
03
Weakness classification
CWE categories help security teams group the underlying software weakness.
04
Source references
External advisories, patches and technical reports attached to this CVE record.