FKIE_CVE-2025-66456

Vulnerability from fkie_nvd - Published: 2025-12-09 20:15 - Updated: 2026-10-14 21:10
Severity
9.8 (Critical) - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Summary
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.
References
security-advisories@github.comhttps://github.com/elysiajs/elysia/commit/26935bf76ebc43b4a43d48b173fc853de43bb51ePatch
security-advisories@github.comhttps://github.com/elysiajs/elysia/commit/3af978663e437dccc6c1a2a3aff4b74e1574849ePatch
security-advisories@github.comhttps://github.com/elysiajs/elysia/pull/1564Issue Tracking, Patch
security-advisories@github.comhttps://github.com/elysiajs/elysia/security/advisories/GHSA-8vch-m3f4-q8jfNot Applicable
security-advisories@github.comhttps://github.com/elysiajs/elysia/security/advisories/GHSA-hxj9-33pp-j2ccExploit, Patch, Vendor Advisory
134c704f-9b21-4f2e-91b3-4a467353bcc0https://github.com/elysiajs/elysia/security/advisories/GHSA-8vch-m3f4-q8jfNot Applicable
134c704f-9b21-4f2e-91b3-4a467353bcc0https://github.com/elysiajs/elysia/security/advisories/GHSA-hxj9-33pp-j2ccExploit, Patch, Vendor Advisory
Impacted products
Vendor Product Version
elysiajs elysia *
To clipboard 

{
  "affected": [
    {
      "affectedData": [
        {
          "product": "elysia",
          "vendor": "elysiajs",
          "versions": [
            {
              "status": "affected",
              "version": "\u003e= 1.4.0, \u003c 1.4.17"
            }
          ]
        }
      ],
      "source": "security-advisories@github.com"
    }
  ],
  "configurations": [
    {
      "nodes": [
        {
          "cpeMatch": [
            {
              "criteria": "cpe:2.3:a:elysiajs:elysia:*:*:*:*:*:node.js:*:*",
              "matchCriteriaId": "41035CD2-DE13-469A-984F-6BC1CCCF2695",
              "versionEndExcluding": "1.4.17",
              "versionStartIncluding": "1.4.0",
              "vulnerable": true
            }
          ],
          "negate": false,
          "operator": "OR"
        }
      ]
    }
  ],
  "cveTags": [],
  "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."
    },
    {
      "lang": "es",
      "value": "Elysia es un framework de Typescript para validaci\u00f3n de solicitudes, inferencia de tipos, documentaci\u00f3n OpenAPI y comunicaci\u00f3n cliente?servidor. Las versiones 1.4.0 hasta 1.4.16 contienen una vulnerabilidad de contaminaci\u00f3n de prototipos en \u0027mergeDeep\u0027 despu\u00e9s de combinar los resultados de dos validaciones de esquema est\u00e1ndar con la misma clave. Debido al orden de combinaci\u00f3n, debe existir un any type que se establece como un guardia independiente, para permitir que la \u0027__proto__ prop\u0027 sea fusionada. Cuando se combina con GHSA?8vch?m3f4?q8jf, esto permite una ejecuci\u00f3n remota de c\u00f3digo (RCE) completa por un atacante. Este problema est\u00e1 corregido en la versi\u00f3n 1.4.17. Como soluci\u00f3n alternativa, elimine la clave \u0027__proto__\u0027 del cuerpo."
    }
  ],
  "id": "CVE-2025-66456",
  "lastModified": "2026-10-14T21:10:00.183",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "NETWORK",
          "availabilityImpact": "HIGH",
          "baseScore": 9.8,
          "baseSeverity": "CRITICAL",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "HIGH",
          "privilegesRequired": "NONE",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
          "version": "3.1"
        },
        "exploitabilityScore": 3.9,
        "impactScore": 5.9,
        "source": "nvd@nist.gov",
        "type": "Primary"
      }
    ],
    "cvssMetricV40": [
      {
        "cvssData": {
          "Automatable": "NOT_DEFINED",
          "Recovery": "NOT_DEFINED",
          "Safety": "NOT_DEFINED",
          "attackComplexity": "LOW",
          "attackRequirements": "PRESENT",
          "attackVector": "NETWORK",
          "availabilityRequirement": "NOT_DEFINED",
          "baseScore": 9.1,
          "baseSeverity": "CRITICAL",
          "confidentialityRequirement": "NOT_DEFINED",
          "exploitMaturity": "NOT_DEFINED",
          "integrityRequirement": "NOT_DEFINED",
          "modifiedAttackComplexity": "NOT_DEFINED",
          "modifiedAttackRequirements": "NOT_DEFINED",
          "modifiedAttackVector": "NOT_DEFINED",
          "modifiedPrivilegesRequired": "NOT_DEFINED",
          "modifiedSubAvailabilityImpact": "NOT_DEFINED",
          "modifiedSubConfidentialityImpact": "NOT_DEFINED",
          "modifiedSubIntegrityImpact": "NOT_DEFINED",
          "modifiedUserInteraction": "NOT_DEFINED",
          "modifiedVulnAvailabilityImpact": "NOT_DEFINED",
          "modifiedVulnConfidentialityImpact": "NOT_DEFINED",
          "modifiedVulnIntegrityImpact": "NOT_DEFINED",
          "privilegesRequired": "NONE",
          "providerUrgency": "NOT_DEFINED",
          "subAvailabilityImpact": "NONE",
          "subConfidentialityImpact": "NONE",
          "subIntegrityImpact": "NONE",
          "userInteraction": "NONE",
          "valueDensity": "NOT_DEFINED",
          "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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X",
          "version": "4.0",
          "vulnAvailabilityImpact": "NONE",
          "vulnConfidentialityImpact": "HIGH",
          "vulnIntegrityImpact": "HIGH",
          "vulnerabilityResponseEffort": "NOT_DEFINED"
        },
        "source": "security-advisories@github.com",
        "type": "Secondary"
      }
    ],
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "id": "CVE-2025-66456",
          "options": [
            {
              "exploitation": "poc"
            },
            {
              "automatable": "no"
            },
            {
              "technicalImpact": "total"
            }
          ],
          "role": "CISA Coordinator",
          "timestamp": "2025-12-09T20:11:35.267669Z",
          "version": "2.0.3"
        }
      }
    ]
  },
  "published": "2025-12-09T20:15:54.760",
  "references": [
    {
      "source": "security-advisories@github.com",
      "tags": [
        "Patch"
      ],
      "url": "https://github.com/elysiajs/elysia/commit/26935bf76ebc43b4a43d48b173fc853de43bb51e"
    },
    {
      "source": "security-advisories@github.com",
      "tags": [
        "Patch"
      ],
      "url": "https://github.com/elysiajs/elysia/commit/3af978663e437dccc6c1a2a3aff4b74e1574849e"
    },
    {
      "source": "security-advisories@github.com",
      "tags": [
        "Issue Tracking",
        "Patch"
      ],
      "url": "https://github.com/elysiajs/elysia/pull/1564"
    },
    {
      "source": "security-advisories@github.com",
      "tags": [
        "Not Applicable"
      ],
      "url": "https://github.com/elysiajs/elysia/security/advisories/GHSA-8vch-m3f4-q8jf"
    },
    {
      "source": "security-advisories@github.com",
      "tags": [
        "Exploit",
        "Patch",
        "Vendor Advisory"
      ],
      "url": "https://github.com/elysiajs/elysia/security/advisories/GHSA-hxj9-33pp-j2cc"
    },
    {
      "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
      "tags": [
        "Not Applicable"
      ],
      "url": "https://github.com/elysiajs/elysia/security/advisories/GHSA-8vch-m3f4-q8jf"
    },
    {
      "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
      "tags": [
        "Exploit",
        "Patch",
        "Vendor Advisory"
      ],
      "url": "https://github.com/elysiajs/elysia/security/advisories/GHSA-hxj9-33pp-j2cc"
    }
  ],
  "sourceIdentifier": "security-advisories@github.com",
  "vulnStatus": "Analyzed",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-1321"
        }
      ],
      "source": "security-advisories@github.com",
      "type": "Secondary"
    }
  ]
}



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