{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-116684", "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa", "state": "PUBLISHED", "assignerShortName": "GitHub_M", "dateReserved": "2026-10-26T20:00:59.829Z", "datePublished": "2026-10-27T19:12:24.255Z", "dateUpdated": "2026-10-27T19:12:24.255Z"}, "containers": {"cna": {"title": "Model Context Protocol Python SDK: Server bearer-token authentication accepts tokens issued for a different resource server", "problemTypes": [{"descriptions": [{"cweId": "CWE-863", "lang": "en", "description": "CWE-863: Incorrect Authorization", "type": "CWE"}]}], "metrics": [{"cvssV3_1": {"attackComplexity": "HIGH", "attackVector": "NETWORK", "availabilityImpact": "NONE", "baseScore": 6.8, "baseSeverity": "MEDIUM", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "privilegesRequired": "LOW", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:N", "version": "3.1"}}], "references": [{"name": "https://github.com/modelcontextprotocol/python-sdk/security/advisories/GHSA-w4fh-qvv9-3v23", "tags": ["x_refsource_CONFIRM"], "url": "https://github.com/modelcontextprotocol/python-sdk/security/advisories/GHSA-w4fh-qvv9-3v23"}, {"name": "https://github.com/modelcontextprotocol/python-sdk/pull/3447", "tags": ["x_refsource_MISC"], "url": "https://github.com/modelcontextprotocol/python-sdk/pull/3447"}, {"name": "https://github.com/modelcontextprotocol/python-sdk/pull/3451", "tags": ["x_refsource_MISC"], "url": "https://github.com/modelcontextprotocol/python-sdk/pull/3451"}, {"name": "https://github.com/modelcontextprotocol/python-sdk/commit/0c9136841ff092987a20700ff9c2c9789bda2f40", "tags": ["x_refsource_MISC"], "url": "https://github.com/modelcontextprotocol/python-sdk/commit/0c9136841ff092987a20700ff9c2c9789bda2f40"}, {"name": "https://github.com/modelcontextprotocol/python-sdk/commit/8c2fa6eabacde869d75568e33b9d466b58c2f512", "tags": ["x_refsource_MISC"], "url": "https://github.com/modelcontextprotocol/python-sdk/commit/8c2fa6eabacde869d75568e33b9d466b58c2f512"}, {"name": "https://github.com/modelcontextprotocol/python-sdk/releases/tag/v1.30.0", "tags": ["x_refsource_MISC"], "url": "https://github.com/modelcontextprotocol/python-sdk/releases/tag/v1.30.0"}, {"name": "https://github.com/modelcontextprotocol/python-sdk/releases/tag/v2.2.0", "tags": ["x_refsource_MISC"], "url": "https://github.com/modelcontextprotocol/python-sdk/releases/tag/v2.2.0"}], "affected": [{"vendor": "modelcontextprotocol", "product": "python-sdk", "versions": [{"version": ">= 1.10.0, < 1.30.0", "status": "affected"}, {"version": ">= 2.0.0, < 2.2.0", "status": "affected"}]}], "providerMetadata": {"orgId": "a0819718-46f1-4df5-94e2-005712e83aaa", "shortName": "GitHub_M", "dateUpdated": "2026-10-27T19:12:24.255Z"}, "descriptions": [{"lang": "en", "value": "The Model Context Protocol Python SDK is the official Python SDK for Model Context Protocol servers and clients. From 1.10.0 until 1.30.0 and 2.2.0, server-side bearer authentication configured through AuthSettings with token_verifier accepts a valid token issued for another service when the authorization server serves multiple resources and the TokenVerifier does not independently validate the aud audience. This resource-confusion flaw lets a token holder authenticate to the wrong MCP server and exercise that token's resulting access. This issue is fixed in versions 1.30.0 and 2.2.0."}], "source": {"advisory": "GHSA-w4fh-qvv9-3v23", "discovery": "UNKNOWN"}}}}

{}

{"affected": [{"affectedData": [{"product": "python-sdk", "vendor": "modelcontextprotocol", "versions": [{"status": "affected", "version": ">= 1.10.0, < 1.30.0"}, {"status": "affected", "version": ">= 2.0.0, < 2.2.0"}]}], "source": "security-advisories@github.com"}], "cveTags": [], "descriptions": [{"lang": "en", "value": "The Model Context Protocol Python SDK is the official Python SDK for Model Context Protocol servers and clients. From 1.10.0 until 1.30.0 and 2.2.0, server-side bearer authentication configured through AuthSettings with token_verifier accepts a valid token issued for another service when the authorization server serves multiple resources and the TokenVerifier does not independently validate the aud audience. This resource-confusion flaw lets a token holder authenticate to the wrong MCP server and exercise that token's resulting access. This issue is fixed in versions 1.30.0 and 2.2.0."}], "id": "CVE-2026-116684", "lastModified": "2026-10-27T20:17:13.307", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "HIGH", "attackVector": "NETWORK", "availabilityImpact": "NONE", "baseScore": 6.8, "baseSeverity": "MEDIUM", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "privilegesRequired": "LOW", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:N", "version": "3.1"}, "exploitabilityScore": 1.6, "impactScore": 5.2, "source": "security-advisories@github.com", "type": "Secondary"}]}, "published": "2026-10-27T20:17:13.307", "references": [{"source": "security-advisories@github.com", "url": "https://github.com/modelcontextprotocol/python-sdk/commit/0c9136841ff092987a20700ff9c2c9789bda2f40"}, {"source": "security-advisories@github.com", "url": "https://github.com/modelcontextprotocol/python-sdk/commit/8c2fa6eabacde869d75568e33b9d466b58c2f512"}, {"source": "security-advisories@github.com", "url": "https://github.com/modelcontextprotocol/python-sdk/pull/3447"}, {"source": "security-advisories@github.com", "url": "https://github.com/modelcontextprotocol/python-sdk/pull/3451"}, {"source": "security-advisories@github.com", "url": "https://github.com/modelcontextprotocol/python-sdk/releases/tag/v1.30.0"}, {"source": "security-advisories@github.com", "url": "https://github.com/modelcontextprotocol/python-sdk/releases/tag/v2.2.0"}, {"source": "security-advisories@github.com", "url": "https://github.com/modelcontextprotocol/python-sdk/security/advisories/GHSA-w4fh-qvv9-3v23"}], "sourceIdentifier": "security-advisories@github.com", "vulnStatus": "Received", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-863"}], "source": "security-advisories@github.com", "type": "Primary"}]}

{}

{"affected": [{"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "semver", "value": "[1.10.0,1.30.0)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "semver", "value": "[2.0.0,2.2.0)"}}], "enrichment": {"confidence": 100.0, "confidence_source": "matching", "scores": [{"score": 100.0, "source": "matching"}]}, "original": {"product": "python-sdk", "source": "cna", "vendor": "modelcontextprotocol"}, "product": "python-sdk", "vendor": "modelcontextprotocol"}], "created": "2026-10-27T20:30:08.564747+00:00", "updated": "2026-10-27T20:30:08.564769+00:00", "vendors": ["modelcontextprotocol", "modelcontextprotocol$PRODUCT$python-sdk"]}