Feast < 0.63.0 Unauthenticated RCE via ApplyFeatureView gRPC Deserialization_CVE-2026-56121

{
    "lastseen": "",
    "description": "Feast before 0.63.0 contains an unsafe deserialization vulnerability that allows unauthenticated or unauthorized attackers to achieve remote code execution by sending a crafted gRPC request to the registry server. The user_defined_function.body field of an OnDemandFeatureView spec is decoded from base64 and passed to dill.loads() before any authorization check is performed, enabling attackers to embed a malicious serialized Python object with an arbitrary __reduce__ method to execute OS commands as the feast service account.",
    "published": "2026-06-24T14:49:11.490Z",
    "modified": "2026-06-24T14:49:11.490Z",
    "type": "cve",
    "title": "Feast < 0.63.0 Unauthenticated RCE via ApplyFeatureView gRPC Deserialization",
    "source": "VulnCheck",
    "references": "https://huntr.com/bounties/d64b8111-180b-46ba-afa3-c877fda2ede6\nhttps://github.com/feast-dev/feast/releases/tag/v0.63.0\nhttps://github.com/feast-dev/feast/commit/835cda8e2c1359f1f496ad72701dbd6a73bdb25a\nhttps://www.vulncheck.com/advisories/feast-unauthenticated-rce-via-applyfeatureview-grpc-deserialization",
    "id": "CVE-2026-56121",
    "bulletinFamily": "",
    "cwe": [
        "CWE-502"
    ],
    "cvelist": null,
    "sourceData": "feast-dev feast 0",
    "sourceHref": "",
    "cvss": {
        "score": 9.3,
        "severity": "CRITICAL",
        "vector": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N",
        "version": "4.0"
    },
    "cvss2": [],
    "cvss3": {
        "version": "",
        "vectorString": "",
        "baseScore": 0,
        "baseSeverity": "",
        "attackVector": "",
        "attackComplexity": "",
        "privilegesRequired": "",
        "userInteraction": "",
        "scope": "",
        "confidentialityImpact": "",
        "integrityImpact": "",
        "availabilityImpact": "",
        "cvssV3": {
            "version": "",
            "vectorString": "",
            "baseScore": 0,
            "baseSeverity": "",
            "attackVector": "",
            "attackComplexity": "",
            "privilegesRequired": "",
            "userInteraction": "",
            "scope": "",
            "confidentialityImpact": "",
            "integrityImpact": "",
            "availabilityImpact": ""
        }
    },
    "href": "",
    "category_name": "CVE",
    "post_link": "",
    "product": "feast",
    "version": "0",
    "vendor": "feast-dev",
    "ai_description": "Unauthenticated remote code execution via unsafe deserialization in Feast before 0.63.0",
    "ai_severity": "Critical",
    "ai_vendor": "feast-dev",
    "ai_product": "feast",
    "ai_version": "< 0.63.0",
    "ai_score": 9.3
}