{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-45781","assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","state":"PUBLISHED","assignerShortName":"GitHub_M","dateReserved":"2026-05-13T07:45:21.252Z","datePublished":"2026-05-14T21:00:49.961Z","dateUpdated":"2026-05-16T01:06:38.302Z"},"containers":{"cna":{"title":"MCP Registry: OCI ownership validation fails open on upstream rate limits, allowing attacker-controlled package claims","problemTypes":[{"descriptions":[{"cweId":"CWE-636","lang":"en","description":"CWE-636: Not Failing Securely ('Failing Open')","type":"CWE"}]}],"metrics":[{"cvssV3_1":{"attackComplexity":"LOW","attackVector":"NETWORK","availabilityImpact":"NONE","baseScore":3.5,"baseSeverity":"LOW","confidentialityImpact":"NONE","integrityImpact":"LOW","privilegesRequired":"LOW","scope":"UNCHANGED","userInteraction":"REQUIRED","vectorString":"CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:N/I:L/A:N","version":"3.1"}}],"references":[{"name":"https://github.com/modelcontextprotocol/registry/security/advisories/GHSA-2v5f-5r6w-p67r","tags":["x_refsource_CONFIRM"],"url":"https://github.com/modelcontextprotocol/registry/security/advisories/GHSA-2v5f-5r6w-p67r"}],"affected":[{"vendor":"modelcontextprotocol","product":"registry","versions":[{"version":"< 1.7.9","status":"affected"}]}],"providerMetadata":{"orgId":"a0819718-46f1-4df5-94e2-005712e83aaa","shortName":"GitHub_M","dateUpdated":"2026-05-14T21:00:49.961Z"},"descriptions":[{"lang":"en","value":"The MCP Registry provides MCP clients with a list of MCP servers, like an app store for MCP servers. Prior to 1.7.9, OCI ownership validation skips label-match check when upstream OCI registry returns HTTP 429, letting any authenticated publisher bind their io.github.<user>/* namespace to OCI images they do not control. internal/validators/registries/oci.go:104-119 fails open on http.StatusTooManyRequests: when the registry's anonymous fetch to the upstream OCI registry is rate-limited, ValidateOCI returns nil and the publish is accepted without ever running the io.modelcontextprotocol.server.name label-match check at lines 122-141. That label check is the only cross-system ownership proof the registry applies to OCI packages — every other registry type (NPM, PyPI, NuGet, MCPB) treats a non-200 upstream response as a hard error. This vulnerability is fixed in 1.7.9."}],"source":{"advisory":"GHSA-2v5f-5r6w-p67r","discovery":"UNKNOWN"}},"adp":[{"references":[{"url":"https://github.com/modelcontextprotocol/registry/security/advisories/GHSA-2v5f-5r6w-p67r","tags":["exploit"]}],"metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-05-16T01:05:36.535544Z","id":"CVE-2026-45781","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":"2026-05-16T01:06:38.302Z"}}]}}