{
  "affected": [
    {
      "affectedData": [
        {
          "product": "taiko-mono",
          "vendor": "taikoxyz",
          "versions": [
            {
              "status": "affected",
              "version": "\u003c= 2.3.1"
            }
          ]
        }
      ],
      "source": "security-advisories@github.com"
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "Taiko Alethia is an Ethereum-equivalent, permissionless, based rollup designed to scale Ethereum without compromising its fundamental properties. In 2.3.1 and earlier, TaikoInbox._verifyBatches (packages/protocol/contracts/layer1/based/TaikoInbox.sol:627-678) advanced the local tid to whatever transition matched the current blockHash before knowing whether that batch would actually be verified. When the loop later broke (e.g., cooldown window not yet passed or transition invalidated), the function still wrote that newer tid into batches[lastVerifiedBatchId].verifiedTransitionId after decrementing batchId. Result: the last verified batch could end up pointing at a transition index from the next batch (often zeroed), corrupting the verified chain pointer."
    },
    {
      "lang": "es",
      "value": "Taiko Alethia es un rollup basado, sin permisos y equivalente a Ethereum, dise\u00f1ado para escalar Ethereum sin comprometer sus propiedades fundamentales. En la versi\u00f3n 2.3.1 y anteriores, TaikoInbox._verifyBatches (packages/protocolo/contracts/layer1/based/TaikoInbox.sol:627-678) avanzaba el tid local a cualquier transici\u00f3n que coincidiera con el blockHash actual antes de saber si ese lote ser\u00eda realmente verificado. Cuando el bucle se romp\u00eda m\u00e1s tarde (por ejemplo, la ventana de enfriamiento a\u00fan no hab\u00eda pasado o la transici\u00f3n fue invalidada), la funci\u00f3n a\u00fan escrib\u00eda ese tid m\u00e1s nuevo en batches[lastVerifiedBatchId].verifiedTransitionId despu\u00e9s de decrementar batchId. Resultado: el \u00faltimo lote verificado podr\u00eda terminar apuntando a un \u00edndice de transici\u00f3n del siguiente lote (a menudo puesto a cero), corrompiendo el puntero de la cadena verificada."
    }
  ],
  "id": "CVE-2025-66559",
  "lastModified": "2026-10-18T15:10:00.097",
  "metrics": {
    "cvssMetricV40": [
      {
        "cvssData": {
          "Automatable": "NOT_DEFINED",
          "Recovery": "NOT_DEFINED",
          "Safety": "NOT_DEFINED",
          "attackComplexity": "LOW",
          "attackRequirements": "NONE",
          "attackVector": "NETWORK",
          "availabilityRequirement": "NOT_DEFINED",
          "baseScore": 8.0,
          "baseSeverity": "HIGH",
          "confidentialityRequirement": "NOT_DEFINED",
          "exploitMaturity": "UNREPORTED",
          "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:N/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N/E:U/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-2025-66559",
          "options": [
            {
              "exploitation": "none"
            },
            {
              "automatable": "yes"
            },
            {
              "technicalImpact": "total"
            }
          ],
          "role": "CISA Coordinator",
          "timestamp": "2025-12-05T17:28:55.262649Z",
          "version": "2.0.3"
        }
      }
    ]
  },
  "published": "2025-12-04T23:15:46.940",
  "references": [
    {
      "source": "security-advisories@github.com",
      "url": "https://github.com/taikoxyz/taiko-mono/commit/379f5cb4ffe9e1945563ab2c7740bc9f4ea004d8"
    },
    {
      "source": "security-advisories@github.com",
      "url": "https://github.com/taikoxyz/taiko-mono/security/advisories/GHSA-5mxh-r33p-6h5x"
    }
  ],
  "sourceIdentifier": "security-advisories@github.com",
  "vulnStatus": "Deferred",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-129"
        }
      ],
      "source": "security-advisories@github.com",
      "type": "Secondary"
    }
  ]
}