{
    "dataType": "CVE_RECORD",
    "dataVersion": "5.2",
    "cveMetadata": {
        "cveId": "CVE-2025-66456",
        "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "state": "PUBLISHED",
        "assignerShortName": "GitHub_M",
        "dateReserved": "2025-12-01T22:51:54.580Z",
        "datePublished": "2025-12-09T19:43:10.252Z",
        "dateUpdated": "2025-12-09T20:35:44.683Z"
    },
    "containers": {
        "cna": {
            "title": "Elysia vulnerable to prototype pollution with multiple standalone schema validation",
            "problemTypes": [
                {
                    "descriptions": [
                        {
                            "cweId": "CWE-1321",
                            "lang": "en",
                            "description": "CWE-1321: Improperly Controlled Modification of Object Prototype Attributes ('Prototype Pollution')",
                            "type": "CWE"
                        }
                    ]
                }
            ],
            "metrics": [
                {
                    "cvssV4_0": {
                        "attackVector": "NETWORK",
                        "attackComplexity": "LOW",
                        "attackRequirements": "PRESENT",
                        "privilegesRequired": "NONE",
                        "userInteraction": "NONE",
                        "vulnConfidentialityImpact": "HIGH",
                        "vulnIntegrityImpact": "HIGH",
                        "vulnAvailabilityImpact": "NONE",
                        "subConfidentialityImpact": "NONE",
                        "subIntegrityImpact": "NONE",
                        "subAvailabilityImpact": "NONE",
                        "baseScore": 9.1,
                        "baseSeverity": "CRITICAL",
                        "vectorString": "CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N",
                        "version": "4.0"
                    }
                }
            ],
            "references": [
                {
                    "name": "https://github.com/elysiajs/elysia/security/advisories/GHSA-hxj9-33pp-j2cc",
                    "tags": [
                        "x_refsource_CONFIRM"
                    ],
                    "url": "https://github.com/elysiajs/elysia/security/advisories/GHSA-hxj9-33pp-j2cc"
                },
                {
                    "name": "https://github.com/elysiajs/elysia/security/advisories/GHSA-8vch-m3f4-q8jf",
                    "tags": [
                        "x_refsource_MISC"
                    ],
                    "url": "https://github.com/elysiajs/elysia/security/advisories/GHSA-8vch-m3f4-q8jf"
                },
                {
                    "name": "https://github.com/elysiajs/elysia/pull/1564",
                    "tags": [
                        "x_refsource_MISC"
                    ],
                    "url": "https://github.com/elysiajs/elysia/pull/1564"
                },
                {
                    "name": "https://github.com/elysiajs/elysia/commit/26935bf76ebc43b4a43d48b173fc853de43bb51e",
                    "tags": [
                        "x_refsource_MISC"
                    ],
                    "url": "https://github.com/elysiajs/elysia/commit/26935bf76ebc43b4a43d48b173fc853de43bb51e"
                },
                {
                    "name": "https://github.com/elysiajs/elysia/commit/3af978663e437dccc6c1a2a3aff4b74e1574849e",
                    "tags": [
                        "x_refsource_MISC"
                    ],
                    "url": "https://github.com/elysiajs/elysia/commit/3af978663e437dccc6c1a2a3aff4b74e1574849e"
                }
            ],
            "affected": [
                {
                    "vendor": "elysiajs",
                    "product": "elysia",
                    "versions": [
                        {
                            "version": ">= 1.4.0, < 1.4.17",
                            "status": "affected"
                        }
                    ]
                }
            ],
            "providerMetadata": {
                "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
                "shortName": "GitHub_M",
                "dateUpdated": "2025-12-09T19:43:10.252Z"
            },
            "descriptions": [
                {
                    "lang": "en",
                    "value": "Elysia is a Typescript framework for request validation, type inference, OpenAPI documentation and client-server communication. Versions 1.4.0 through 1.4.16 contain a prototype pollution vulnerability in `mergeDeep` after merging results of two standard schema validations with the same key. Due to the ordering of merging, there must be an any type that is set as a standalone guard, to allow for the `__proto__ prop` to be merged. When combined with GHSA-8vch-m3f4-q8jf this allows for a full RCE by an attacker. This issue is fixed in version 1.4.17. To workaround, remove the `__proto__ key` from body."
                }
            ],
            "source": {
                "advisory": "GHSA-hxj9-33pp-j2cc",
                "discovery": "UNKNOWN"
            }
        },
        "adp": [
            {
                "references": [
                    {
                        "url": "https://github.com/elysiajs/elysia/security/advisories/GHSA-hxj9-33pp-j2cc",
                        "tags": [
                            "exploit"
                        ]
                    },
                    {
                        "url": "https://github.com/elysiajs/elysia/security/advisories/GHSA-8vch-m3f4-q8jf",
                        "tags": [
                            "exploit"
                        ]
                    }
                ],
                "metrics": [
                    {
                        "other": {
                            "type": "ssvc",
                            "content": {
                                "timestamp": "2025-12-09T20:11:35.267669Z",
                                "id": "CVE-2025-66456",
                                "options": [
                                    {
                                        "Exploitation": "poc"
                                    },
                                    {
                                        "Automatable": "no"
                                    },
                                    {
                                        "Technical Impact": "total"
                                    }
                                ],
                                "role": "CISA Coordinator",
                                "version": "2.0.3"
                            }
                        }
                    }
                ],
                "title": "CISA ADP Vulnrichment",
                "providerMetadata": {
                    "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
                    "shortName": "CISA-ADP",
                    "dateUpdated": "2025-12-09T20:35:44.683Z"
                }
            }
        ]
    }
}