{"id":"CVE-2026-45781","sourceIdentifier":"security-advisories@github.com","published":"2026-05-14T21:16:48.480","lastModified":"2026-06-17T10:52:33.167","vulnStatus":"Deferred","cveTags":[],"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."}],"affected":[{"source":"security-advisories@github.com","affectedData":[{"vendor":"modelcontextprotocol","product":"registry","versions":[{"version":"< 1.7.9","status":"affected"}]}]}],"metrics":{"cvssMetricV31":[{"source":"security-advisories@github.com","type":"Secondary","cvssData":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:N/I:L/A:N","baseScore":3.5,"baseSeverity":"LOW","attackVector":"NETWORK","attackComplexity":"LOW","privilegesRequired":"LOW","userInteraction":"REQUIRED","scope":"UNCHANGED","confidentialityImpact":"NONE","integrityImpact":"LOW","availabilityImpact":"NONE"},"exploitabilityScore":2.1,"impactScore":1.4}],"ssvcV203":[{"source":"134c704f-9b21-4f2e-91b3-4a467353bcc0","ssvcData":{"timestamp":"2026-05-16T01:05:36.535544Z","id":"CVE-2026-45781","options":[{"exploitation":"poc"},{"automatable":"no"},{"technicalImpact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}]},"weaknesses":[{"source":"security-advisories@github.com","type":"Secondary","description":[{"lang":"en","value":"CWE-636"}]}],"references":[{"url":"https://github.com/modelcontextprotocol/registry/security/advisories/GHSA-2v5f-5r6w-p67r","source":"security-advisories@github.com"},{"url":"https://github.com/modelcontextprotocol/registry/security/advisories/GHSA-2v5f-5r6w-p67r","source":"134c704f-9b21-4f2e-91b3-4a467353bcc0"}]}