CVE-2026-0621

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Un atacante puede explotar esto al proporcionar una URI maliciosa que hace que el proceso de Node.js deje de responder, lo que lleva a una denegaci\u00f3n de servicio."}], "id": "CVE-2026-0621", "lastModified": "2026-10-26T21:10:00.170", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "LOW", "attackVector": "NETWORK", "availabilityImpact": "HIGH", "baseScore": 7.5, "baseSeverity": "HIGH", "confidentialityImpact": "NONE", "integrityImpact": "NONE", "privilegesRequired": "NONE", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H", "version": "3.1"}, "exploitabilityScore": 3.9, "impactScore": 3.6, "source": "nvd@nist.gov", "type": "Primary"}], "cvssMetricV40": [{"cvssData": {"Automatable": "NOT_DEFINED", "Recovery": "NOT_DEFINED", "Safety": "NOT_DEFINED", "attackComplexity": "LOW", "attackRequirements": "NONE", "attackVector": "NETWORK", "availabilityRequirement": "NOT_DEFINED", "baseScore": 8.7, "baseSeverity": "HIGH", "confidentialityRequirement": "NOT_DEFINED", "exploitMaturity": "NOT_DEFINED", "integrityRequirement": "NOT_DEFINED", "modifiedAttackComplexity": "NOT_DEFINED", "modifiedAttackRequirements": "NOT_DEFINED", "modifiedAttackVector": "NOT_DEFINED", "modifiedPrivilegesRequired": "NOT_DEFINED", "modifiedSubAvailabilityImpact": "NOT_DEFINED", "modifiedSubConfidentialityImpact": "NOT_DEFINED", "modifiedSubIntegrityImpact": "NOT_DEFINED", "modifiedUserInteraction": "NOT_DEFINED", "modifiedVulnAvailabilityImpact": "NOT_DEFINED", "modifiedVulnConfidentialityImpact": "NOT_DEFINED", "modifiedVulnIntegrityImpact": "NOT_DEFINED", "privilegesRequired": "NONE", "providerUrgency": "NOT_DEFINED", "subAvailabilityImpact": "NONE", "subConfidentialityImpact": "NONE", "subIntegrityImpact": "NONE", "userInteraction": "NONE", "valueDensity": "NOT_DEFINED", "vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/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", "version": "4.0", "vulnAvailabilityImpact": "HIGH", "vulnConfidentialityImpact": "NONE", "vulnIntegrityImpact": "NONE", "vulnerabilityResponseEffort": "NOT_DEFINED"}, "source": "disclosure@vulncheck.com", "type": "Secondary"}], "ssvcV203": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "ssvcData": {"id": "CVE-2026-0621", "options": [{"exploitation": "poc"}, {"automatable": "yes"}, {"technicalImpact": "partial"}], "role": "CISA Coordinator", "timestamp": "2026-01-05T21:07:47.543163Z", "version": "2.0.3"}}]}, "published": "2026-01-05T21:16:14.533", "references": [{"source": "disclosure@vulncheck.com", "tags": ["Exploit", "Issue Tracking"], "url": "https://github.com/modelcontextprotocol/typescript-sdk/issues/965"}, {"source": "disclosure@vulncheck.com", "tags": ["Third Party Advisory"], "url": "https://www.vulncheck.com/advisories/mcp-typescript-sdk-uritemplate-exploded-array-pattern-redos"}, {"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "tags": ["Exploit", "Issue Tracking"], "url": "https://github.com/modelcontextprotocol/typescript-sdk/issues/965"}], "sourceIdentifier": "disclosure@vulncheck.com", "vulnStatus": "Analyzed", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-1333"}], "source": "disclosure@vulncheck.com", "type": "Secondary"}]}

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{"analysis": {"en": {"generated_at": "2026-04-18T08:18:54.061198+00:00", "value": {"mitigation_remediation": ["Upgrade the MCP TypeScript SDK to the latest version released by Anthropic, which includes the vulnerability fix.", "Validate or sanitize incoming URIs to reject or normalize exploded array patterns before they reach the UriTemplate class, thereby preventing catastrophic backtracking.", "Implement application\u2011level resource limits, such as CPU throttling or process isolation for the Node.js runtime, to mitigate the impact should any denial\u2011of\u2011service attempt occur."], "summary": {"action": "Immediate Patch", "impact": "Denial of Service via ReDoS"}, "threat_synthesis": {"affected_systems": "Anthropic\u2019s MCP TypeScript SDK versions up to and including 1.25.1 are affected. The SDK is typically used in Node.js environments to resolve or match URIs against templates. Any deployment that integrates these SDK versions, regardless of the specific application, is vulnerable if it processes user\u2011supplied URIs containing exploded array patterns.", "description_and_impact": "The vulnerability is a regular expression denial of service in the UriTemplate class of the Anthropic MCP TypeScript SDK. When processing RFC\u202f6570 exploded array patterns, the SDK builds a dynamic regular expression that contains nested quantifiers. An attacker can craft a URI containing a large exploded array pattern that forces catastrophic backtracking, exhausting CPU resources and rendering the Node.js process unresponsive. The impact is a denial of service aimed at disrupting application availability.", "risk_and_exploitability": "The CVSS score is 8.7, indicating a high severity. The EPSS score is less than 1%, showing a low probability of exploitation at present, and the vulnerability is not listed in CISA\u2019s KEV catalog. The attack requires only the ability to supply a crafted URI\u2014no authentication or privileged access is necessary\u2014making the exploit path straightforward for remote users who can invoke the affected SDK functionality. The primary vector is remote, via HTTP requests or any API surface that forwards URIs to the SDK for matching."}}}}, "created": "2026-01-06T14:16:36.773430+00:00", "updated": "2026-04-18T08:30:35.821356+00:00", "vendors": ["anthropic", "anthropic$PRODUCT$mcp_typescript_sdk"]}