{"api_version":"1","generated_at":"2026-05-15T05:22:29+00:00","cve":"CVE-2026-45781","urls":{"html":"https://cve.report/CVE-2026-45781","api":"https://cve.report/api/cve/CVE-2026-45781.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2026-45781","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-45781"},"summary":{"title":"MCP Registry: OCI ownership validation fails open on upstream rate limits, allowing attacker-controlled package claims","description":"The MCP Registry provides MCP clients with a list of MCP servers, like an app store for MCP servers. 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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. 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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.","Type":"Description","Title":"MCP Registry: OCI ownership validation fails open on upstream ra"}]}}}