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.
Advisories
| Source | ID | Title |
|---|---|---|
Github GHSA |
GHSA-rjr6-rcgv-9m7m | MCP Ruby SDK: Streamable HTTP transport lacks DNS-rebinding (Host/Origin) protection |
Fixes
Solution
No solution given by the vendor.
Workaround
No workaround given by the vendor.
References
History
Wed, 29 Jul 2026 21:00:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| First Time appeared |
Modelcontextprotocol
Modelcontextprotocol ruby-sdk |
|
| Vendors & Products |
Modelcontextprotocol
Modelcontextprotocol ruby-sdk |
Wed, 29 Jul 2026 20:30:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Metrics |
ssvc
|
Wed, 29 Jul 2026 19:30:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| 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. | |
| Title | MCP Ruby SDK: Streamable HTTP transport lacks DNS-rebinding (Host/Origin) protection | |
| Weaknesses | CWE-346 CWE-350 |
|
| References |
| |
| Metrics |
cvssV4_0
|
Projects
Sign in to view the affected projects.
Status: PUBLISHED
Assigner: GitHub_M
Published:
Updated: 2026-07-29T19:35:10.375Z
Reserved: 2026-07-15T16:54:55.816Z
Link: CVE-2026-63118
Updated: 2026-07-29T19:35:05.445Z
No data.
No data.
OpenCVE Enrichment
Updated: 2026-08-03T13:00:07Z
Github GHSA