MCP Registry: OCI ownership validation fails open on upstream rate limits, allowing attacker-controlled package claims_CVE-2026-45781

{
    "lastseen": "",
    "description": "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 \u2014 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.",
    "published": "2026-05-14T21:00:49.961Z",
    "modified": "2026-05-14T21:00:49.961Z",
    "type": "cve",
    "title": "MCP Registry: OCI ownership validation fails open on upstream rate limits, allowing attacker-controlled package claims",
    "source": "GitHub_M",
    "references": "https://github.com/modelcontextprotocol/registry/security/advisories/GHSA-2v5f-5r6w-p67r",
    "id": "CVE-2026-45781",
    "bulletinFamily": "",
    "cwe": [
        "CWE-636"
    ],
    "cvelist": null,
    "sourceData": "modelcontextprotocol registry < 1.7.9",
    "sourceHref": "",
    "cvss": {
        "score": 3.5,
        "severity": "LOW",
        "vector": "CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:N/I:L/A:N",
        "version": "3.1"
    },
    "cvss2": [],
    "cvss3": {
        "version": "",
        "vectorString": "",
        "baseScore": 0,
        "baseSeverity": "",
        "attackVector": "",
        "attackComplexity": "",
        "privilegesRequired": "",
        "userInteraction": "",
        "scope": "",
        "confidentialityImpact": "",
        "integrityImpact": "",
        "availabilityImpact": "",
        "cvssV3": {
            "version": "",
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            "baseScore": 0,
            "baseSeverity": "",
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        }
    },
    "href": "",
    "category_name": "CVE",
    "post_link": "",
    "product": "registry",
    "version": "< 1.7.9",
    "vendor": "modelcontextprotocol",
    "ai_description": "",
    "ai_severity": "",
    "ai_vendor": "",
    "ai_product": "",
    "ai_version": "",
    "ai_score": 0
}