{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-67431", "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa", "state": "PUBLISHED", "assignerShortName": "GitHub_M", "dateReserved": "2026-07-29T15:07:24.991Z", "datePublished": "2026-07-29T19:15:32.340Z", "dateUpdated": "2026-07-29T19:15:32.340Z"}, "containers": {"cna": {"title": "MCP Ruby SDK: Ruby SSE Session Poisoning", "problemTypes": [{"descriptions": [{"cweId": "CWE-284", "lang": "en", "description": "CWE-284: Improper Access Control", "type": "CWE"}]}], "metrics": [{"cvssV4_0": {"attackVector": "NETWORK", "attackComplexity": "LOW", "attackRequirements": "PRESENT", "privilegesRequired": "NONE", "userInteraction": "NONE", "vulnConfidentialityImpact": "NONE", "vulnIntegrityImpact": "HIGH", "vulnAvailabilityImpact": "LOW", "subConfidentialityImpact": "NONE", "subIntegrityImpact": "NONE", "subAvailabilityImpact": "NONE", "baseScore": 8.3, "baseSeverity": "HIGH", "vectorString": "CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:H/VA:L/SC:N/SI:N/SA:N", "version": "4.0"}}], "references": [{"name": "https://github.com/modelcontextprotocol/ruby-sdk/security/advisories/GHSA-5p9g-j988-pcwv", "tags": ["x_refsource_CONFIRM"], "url": "https://github.com/modelcontextprotocol/ruby-sdk/security/advisories/GHSA-5p9g-j988-pcwv"}, {"name": "https://github.com/modelcontextprotocol/ruby-sdk/commit/35466605319a34e4c7808712ae9bb1ca1afb2356", "tags": ["x_refsource_MISC"], "url": "https://github.com/modelcontextprotocol/ruby-sdk/commit/35466605319a34e4c7808712ae9bb1ca1afb2356"}, {"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": "2026-07-29T19:15:32.340Z"}, "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 bind a session ID to a session owner, allowing an attacker with a stolen session ID to send tools/call requests that execute in the victim's session. This issue is fixed in version 0.23.0."}], "source": {"advisory": "GHSA-5p9g-j988-pcwv", "discovery": "UNKNOWN"}}}}

{}

{}

{}

{"affected": [{"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "semver", "value": "[0,0.23.0)"}}], "enrichment": {"confidence": 100.0, "confidence_source": "matching", "scores": [{"score": 100.0, "source": "matching"}]}, "original": {"product": "ruby-sdk", "source": "cna", "vendor": "modelcontextprotocol"}, "product": "ruby-sdk", "vendor": "modelcontextprotocol"}], "created": "2026-07-29T20:45:06.306633+00:00", "updated": "2026-07-29T20:45:06.306660+00:00", "vendors": ["modelcontextprotocol", "modelcontextprotocol$PRODUCT$ruby-sdk"]}