MCP Registry: GitHub OIDC tokens replayable across registry deployments due to shared audience_CVE-2026-44428

{
    "lastseen": "",
    "description": "The MCP Registry provides MCP clients with a list of MCP servers, like an app store for MCP servers. Prior to 1.7.6, the client-side and server-side GitHub OIDC flow is bound only to a global audience string, not to the specific registry instance being targeted. On the client side, the publisher always appends audience=mcp-registry when requesting the GitHub Actions ID token, regardless of the selected --registry URL. On the server side, the exchange endpoint validates only that same fixed audience and then derives publish permissions directly from repository_owner. As a result, a token legitimately obtained while interacting with one registry deployment remains acceptable to any other deployment that shares the same code and audience string. This vulnerability is fixed in 1.7.6.",
    "published": "2026-05-14T21:09:10.092Z",
    "modified": "2026-05-14T21:09:10.092Z",
    "type": "cve",
    "title": "MCP Registry: GitHub OIDC tokens replayable across registry deployments due to shared audience",
    "source": "GitHub_M",
    "references": "https://github.com/modelcontextprotocol/registry/security/advisories/GHSA-95c3-6vvw-4mrq",
    "id": "CVE-2026-44428",
    "bulletinFamily": "",
    "cwe": [
        "CWE-918"
    ],
    "cvelist": null,
    "sourceData": "modelcontextprotocol registry < 1.7.6",
    "sourceHref": "",
    "cvss": {
        "score": 2.1,
        "severity": "LOW",
        "vector": "CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:A/VC:N/VI:L/VA:N/SC:N/SI:L/SA:N",
        "version": "4.0"
    },
    "cvss2": [],
    "cvss3": {
        "version": "",
        "vectorString": "",
        "baseScore": 0,
        "baseSeverity": "",
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        "attackComplexity": "",
        "privilegesRequired": "",
        "userInteraction": "",
        "scope": "",
        "confidentialityImpact": "",
        "integrityImpact": "",
        "availabilityImpact": "",
        "cvssV3": {
            "version": "",
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            "baseScore": 0,
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        }
    },
    "href": "",
    "category_name": "CVE",
    "post_link": "",
    "product": "registry",
    "version": "< 1.7.6",
    "vendor": "modelcontextprotocol",
    "ai_description": "",
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    "ai_score": 0
}