CVE-2026-33946

{"id": "CVE-2026-33946", "cveTags": [], "metrics": {"ssvcV203": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "ssvcData": {"id": "CVE-2026-33946", "role": "CISA Coordinator", "options": [{"exploitation": "poc"}, {"automatable": "yes"}, {"technicalImpact": "partial"}], "version": "2.0.3", "timestamp": "2026-03-30T18:42:40.211983Z"}}], "cvssMetricV31": [{"type": "Primary", "source": "nvd@nist.gov", "cvssData": {"scope": "UNCHANGED", "version": "3.1", "baseScore": 5.9, "attackVector": "NETWORK", "baseSeverity": "MEDIUM", "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N", "integrityImpact": "NONE", "userInteraction": "NONE", "attackComplexity": "HIGH", "availabilityImpact": "NONE", "privilegesRequired": "NONE", "confidentialityImpact": "HIGH"}, "impactScore": 3.6, "exploitabilityScore": 2.2}], "cvssMetricV40": [{"type": "Secondary", "source": "security-advisories@github.com", "cvssData": {"Safety": "NOT_DEFINED", "version": "4.0", "Recovery": "NOT_DEFINED", "baseScore": 8.2, "Automatable": "NOT_DEFINED", "attackVector": "NETWORK", "baseSeverity": "HIGH", "valueDensity": "NOT_DEFINED", "vectorString": "CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X", "exploitMaturity": "NOT_DEFINED", "providerUrgency": "NOT_DEFINED", "userInteraction": "NONE", "attackComplexity": "LOW", "attackRequirements": "PRESENT", "privilegesRequired": "NONE", "subIntegrityImpact": "NONE", "vulnIntegrityImpact": "NONE", "integrityRequirement": "NOT_DEFINED", "modifiedAttackVector": "NOT_DEFINED", "subAvailabilityImpact": "NONE", "vulnAvailabilityImpact": "NONE", "availabilityRequirement": "NOT_DEFINED", "modifiedUserInteraction": "NOT_DEFINED", "modifiedAttackComplexity": "NOT_DEFINED", "subConfidentialityImpact": "NONE", "vulnConfidentialityImpact": "HIGH", "confidentialityRequirement": "NOT_DEFINED", "modifiedAttackRequirements": "NOT_DEFINED", "modifiedPrivilegesRequired": "NOT_DEFINED", "modifiedSubIntegrityImpact": "NOT_DEFINED", "modifiedVulnIntegrityImpact": "NOT_DEFINED", "vulnerabilityResponseEffort": "NOT_DEFINED", "modifiedSubAvailabilityImpact": "NOT_DEFINED", "modifiedVulnAvailabilityImpact": "NOT_DEFINED", "modifiedSubConfidentialityImpact": "NOT_DEFINED", "modifiedVulnConfidentialityImpact": "NOT_DEFINED"}}]}, "affected": [{"source": "security-advisories@github.com", "affectedData": [{"vendor": "modelcontextprotocol", "product": "ruby-sdk", "versions": [{"status": "affected", "version": "< 0.9.2"}]}]}], "published": "2026-03-27T22:16:21.580", "references": [{"url": "https://github.com/modelcontextprotocol/csharp-sdk/blob/main/src/ModelContextProtocol.AspNetCore/SseHandler.cs#L93-L97", "tags": ["Patch"], "source": "security-advisories@github.com"}, {"url": "https://github.com/modelcontextprotocol/go-sdk/blob/main/mcp/streamable.go#L281C1-L288C2", "tags": ["Patch"], "source": "security-advisories@github.com"}, {"url": "https://github.com/modelcontextprotocol/python-sdk/blob/main/src/mcp/server/streamable_http.py#L680-L685", "tags": ["Patch"], "source": "security-advisories@github.com"}, {"url": "https://github.com/modelcontextprotocol/ruby-sdk/blob/main/examples/streamable_http_server.rb", "tags": ["Patch"], "source": "security-advisories@github.com"}, {"url": "https://github.com/modelcontextprotocol/ruby-sdk/commit/db40143402d65b4fb6923cec42d2d72cb89b3874", "tags": ["Patch"], "source": "security-advisories@github.com"}, {"url": "https://github.com/modelcontextprotocol/ruby-sdk/releases/tag/v0.9.2", "tags": ["Product", "Release Notes"], "source": "security-advisories@github.com"}, {"url": "https://github.com/modelcontextprotocol/ruby-sdk/security/advisories/GHSA-qvqr-5cv7-wh35", "tags": ["Exploit", "Vendor Advisory"], "source": "security-advisories@github.com"}, {"url": "https://hackerone.com/reports/3556146", "tags": ["Permissions Required"], "source": "security-advisories@github.com"}, {"url": "https://github.com/modelcontextprotocol/ruby-sdk/security/advisories/GHSA-qvqr-5cv7-wh35", "tags": ["Exploit", "Vendor Advisory"], "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0"}], "vulnStatus": "Analyzed", "weaknesses": [{"type": "Secondary", "source": "security-advisories@github.com", "description": [{"lang": "en", "value": "CWE-384"}, {"lang": "en", "value": "CWE-639"}]}, {"type": "Primary", "source": "nvd@nist.gov", "description": [{"lang": "en", "value": "CWE-384"}]}], "descriptions": [{"lang": "en", "value": "MCP Ruby SDK is the official Ruby SDK for Model Context Protocol servers and clients. Prior to version 0.9.2, the Ruby SDK's streamable_http_transport.rb implementation contains a session hijacking vulnerability. An attacker who obtains a valid session ID can completely hijack the victim's Server-Sent Events (SSE) stream and intercept all real-time data. Version 0.9.2 contains a patch."}, {"lang": "es", "value": "MCP Ruby SDK es el SDK oficial de Ruby para servidores y clientes del Protocolo de Contexto de Modelo. Antes de la versi\u00f3n 0.9.2, la implementaci\u00f3n streamable_http_transport.rb del SDK de Ruby contiene una vulnerabilidad de secuestro de sesi\u00f3n. Un atacante que obtiene un ID de sesi\u00f3n v\u00e1lido puede secuestrar completamente el flujo de Eventos Enviados por el Servidor (SSE) de la v\u00edctima e interceptar todos los datos en tiempo real. La versi\u00f3n 0.9.2 contiene un parche."}], "lastModified": "2026-10-26T21:10:00.170", "configurations": [{"nodes": [{"negate": false, "cpeMatch": [{"criteria": "cpe:2.3:a:lfprojects:mcp_ruby_sdk:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "BA740303-1659-4AA5-BF51-441A6D3B8B7C", "versionEndExcluding": "0.9.2"}], "operator": "OR"}]}], "sourceIdentifier": "security-advisories@github.com"}