{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-63118", "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa", "state": "PUBLISHED", "assignerShortName": "GitHub_M", "dateReserved": "2026-07-15T16:54:55.816Z", "datePublished": "2026-07-29T19:07:33.452Z", "dateUpdated": "2026-07-29T19:35:10.375Z"}, "containers": {"cna": {"title": "MCP Ruby SDK: Streamable HTTP transport lacks DNS-rebinding (Host/Origin) protection", "problemTypes": [{"descriptions": [{"cweId": "CWE-346", "lang": "en", "description": "CWE-346: Origin Validation Error", "type": "CWE"}]}, {"descriptions": [{"cweId": "CWE-350", "lang": "en", "description": "CWE-350: Reliance on Reverse DNS Resolution for a Security-Critical Action", "type": "CWE"}]}], "metrics": [{"cvssV4_0": {"attackVector": "NETWORK", "attackComplexity": "LOW", "attackRequirements": "PRESENT", "privilegesRequired": "NONE", "userInteraction": "ACTIVE", "vulnConfidentialityImpact": "HIGH", "vulnIntegrityImpact": "NONE", "vulnAvailabilityImpact": "NONE", "subConfidentialityImpact": "HIGH", "subIntegrityImpact": "NONE", "subAvailabilityImpact": "NONE", "baseScore": 6.9, "baseSeverity": "MEDIUM", "vectorString": "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", "version": "4.0"}}], "references": [{"name": "https://github.com/modelcontextprotocol/ruby-sdk/security/advisories/GHSA-rjr6-rcgv-9m7m", "tags": ["x_refsource_CONFIRM"], "url": "https://github.com/modelcontextprotocol/ruby-sdk/security/advisories/GHSA-rjr6-rcgv-9m7m"}, {"name": "https://github.com/modelcontextprotocol/ruby-sdk/commit/ba543083a7594e7892b29464b89091816446ff7a", "tags": ["x_refsource_MISC"], "url": "https://github.com/modelcontextprotocol/ruby-sdk/commit/ba543083a7594e7892b29464b89091816446ff7a"}, {"name": "https://github.com/modelcontextprotocol/ruby-sdk/releases/tag/v0.23.0", "tags": ["x_refsource_MISC"], "url": "https://github.com/modelcontextprotocol/ruby-sdk/releases/tag/v0.23.0"}], "affected": [{"vendor": "modelcontextprotocol", "product": "ruby-sdk", "versions": [{"version": "< 0.23.0", "status": "affected"}]}], "providerMetadata": {"orgId": "a0819718-46f1-4df5-94e2-005712e83aaa", "shortName": "GitHub_M", "dateUpdated": "2026-07-29T19:07:33.452Z"}, "descriptions": [{"lang": "en", "value": "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."}], "source": {"advisory": "GHSA-rjr6-rcgv-9m7m", "discovery": "UNKNOWN"}}, "adp": [{"references": [{"url": "https://github.com/modelcontextprotocol/ruby-sdk/security/advisories/GHSA-rjr6-rcgv-9m7m", "tags": ["exploit"]}], "metrics": [{"other": {"type": "ssvc", "content": {"timestamp": "2026-07-29T19:34:40.295615Z", "id": "CVE-2026-63118", "options": [{"Exploitation": "poc"}, {"Automatable": "no"}, {"Technical Impact": "partial"}], "role": "CISA Coordinator", "version": "2.0.3"}}}], "title": "CISA ADP Vulnrichment", "providerMetadata": {"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-07-29T19:35:10.375Z"}}]}}

{"dataType": "CVE_RECORD", "containers": {"adp": [{"title": "CISA ADP Vulnrichment", "metrics": [{"other": {"type": "ssvc", "content": {"id": "CVE-2026-63118", "role": "CISA Coordinator", "options": [{"Exploitation": "poc"}, {"Automatable": "no"}, {"Technical Impact": "partial"}], "version": "2.0.3", "timestamp": "2026-07-29T19:34:40.295615Z"}}}], "references": [{"url": "https://github.com/modelcontextprotocol/ruby-sdk/security/advisories/GHSA-rjr6-rcgv-9m7m", "tags": ["exploit"]}], "providerMetadata": {"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-07-29T19:35:05.445Z"}}], "cna": {"title": "MCP Ruby SDK: Streamable HTTP transport lacks DNS-rebinding (Host/Origin) protection", "source": {"advisory": "GHSA-rjr6-rcgv-9m7m", "discovery": "UNKNOWN"}, "metrics": [{"cvssV4_0": {"version": "4.0", "baseScore": 6.9, "attackVector": "NETWORK", "baseSeverity": "MEDIUM", "vectorString": "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", "userInteraction": "ACTIVE", "attackComplexity": "LOW", "attackRequirements": "PRESENT", "privilegesRequired": "NONE", "subIntegrityImpact": "NONE", "vulnIntegrityImpact": "NONE", "subAvailabilityImpact": "NONE", "vulnAvailabilityImpact": "NONE", "subConfidentialityImpact": "HIGH", "vulnConfidentialityImpact": "HIGH"}}], "affected": [{"vendor": "modelcontextprotocol", "product": "ruby-sdk", "versions": [{"status": "affected", "version": "< 0.23.0"}]}], "references": [{"url": "https://github.com/modelcontextprotocol/ruby-sdk/security/advisories/GHSA-rjr6-rcgv-9m7m", "name": "https://github.com/modelcontextprotocol/ruby-sdk/security/advisories/GHSA-rjr6-rcgv-9m7m", "tags": ["x_refsource_CONFIRM"]}, {"url": "https://github.com/modelcontextprotocol/ruby-sdk/commit/ba543083a7594e7892b29464b89091816446ff7a", "name": "https://github.com/modelcontextprotocol/ruby-sdk/commit/ba543083a7594e7892b29464b89091816446ff7a", "tags": ["x_refsource_MISC"]}, {"url": "https://github.com/modelcontextprotocol/ruby-sdk/releases/tag/v0.23.0", "name": "https://github.com/modelcontextprotocol/ruby-sdk/releases/tag/v0.23.0", "tags": ["x_refsource_MISC"]}], "descriptions": [{"lang": "en", "value": "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."}], "problemTypes": [{"descriptions": [{"lang": "en", "type": "CWE", "cweId": "CWE-346", "description": "CWE-346: Origin Validation Error"}]}, {"descriptions": [{"lang": "en", "type": "CWE", "cweId": "CWE-350", "description": "CWE-350: Reliance on Reverse DNS Resolution for a Security-Critical Action"}]}], "providerMetadata": {"orgId": "a0819718-46f1-4df5-94e2-005712e83aaa", "shortName": "GitHub_M", "dateUpdated": "2026-07-29T19:07:33.452Z"}}}, "cveMetadata": {"cveId": "CVE-2026-63118", "state": "PUBLISHED", "dateUpdated": "2026-07-29T19:35:10.375Z", "dateReserved": "2026-07-15T16:54:55.816Z", "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa", "datePublished": "2026-07-29T19:07:33.452Z", "assignerShortName": "GitHub_M"}, "dataVersion": "5.2"}

{}

{}

{"affected": [{"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "semver", "value": "[0,0.23.0)"}}], "enrichment": {"confidence": 95.0, "confidence_source": "inferred", "scores": [{"score": 95.0, "source": "inferred"}, {"score": 100.0, "source": "matching"}]}, "original": {"product": "ruby-sdk", "source": "cna", "vendor": "modelcontextprotocol"}, "product": "ruby-sdk", "vendor": "modelcontextprotocol"}], "created": "2026-07-29T20:45:06.307581+00:00", "updated": "2026-07-29T20:45:06.307600+00:00", "vendors": ["modelcontextprotocol", "modelcontextprotocol$PRODUCT$ruby-sdk"]}