6.9
Medium
CVE-2026-63118 MCP Ruby SDK is the official Ruby SDK for Model Context Protocol servers and clients
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.
Affected products and versions
| Product | Affected versions | Fixed in |
|---|---|---|
| ruby-sdk 0.23 | earliest → < 0.23.0 | 0.23.0 |
References
- github.com github.com
- github.com github.com
- github.com github.com
Timeline
- Published
- Last modified
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CVE-2026-63119
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CVE-2026-67430
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5.3
Medium