CVE-2026-56392

{
  "id": "CVE-2026-56392",
  "sourceIdentifier": "[email protected]",
  "published": "2026-07-24T09:16:25.147",
  "lastModified": "2026-10-24T13:10:00.147",
  "vulnStatus": "Analyzed",
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "GNU coreutils unexpand is vulnerable to a heap-based buffer overflow due to an integer overflow during buffer allocation when processing large tab stop (-t) values. The multiplication used to calculate the allocation size can wrap around, resulting in an undersized buffer.\nWhen processing crafted input, subsequent writes exceed the allocated memory, leading to an out‑of‑bounds heap write.\n\nWhen running GNU coreutils unexpand with attacker-provided large tab stop (-t) arguments, this behavior leads to a crash and potentially achieve a heap write primitive depending on memory layout.\n\n\n\n\n\n\n\n\n\n\nThis issue has been fixed in the commit b60a159fdc5bfcf9988d3a4cb6f53abe8ad5d35d"
    },
    {
      "lang": "es",
      "value": "GNU coreutils unexpand es vulnerable a un desbordamiento de búfer basado en montículo debido a un desbordamiento de entero durante la asignación de búfer al procesar valores grandes de tabulación (-t). La multiplicación utilizada para calcular el tamaño de la asignación puede dar la vuelta, lo que resulta en un búfer de tamaño insuficiente.\nAl procesar entrada manipulada, las escrituras subsiguientes exceden la memoria asignada, lo que lleva a una escritura fuera de límites en el montículo.\n\nAl ejecutar GNU coreutils unexpand con argumentos de tabulación (-t) grandes proporcionados por el atacante, este comportamiento lleva a un fallo y potencialmente logra una primitiva de escritura en el montículo dependiendo del diseño de la memoria.\n\nEste problema ha sido corregido en el commit b60a159fdc5bfcf9988d3a4cb6f53abe8ad5d35d"
    }
  ],
  "affected": [
    {
      "source": "[email protected]",
      "affectedData": [
        {
          "vendor": "GNU",
          "product": "coreutils",
          "defaultStatus": "unaffected",
          "modules": [
            "unexpand"
          ],
          "versions": [
            {
              "version": "0",
              "lessThanOrEqual": "9.11",
              "versionType": "custom",
              "status": "affected"
            }
          ]
        }
      ]
    }
  ],
  "metrics": {
    "cvssMetricV40": [
      {
        "source": "[email protected]",
        "type": "Secondary",
        "cvssData": {
          "version": "4.0",
          "vectorString": "CVSS:4.0/AV:L/AC:L/AT:P/PR:N/UI:A/VC:N/VI:L/VA:L/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",
          "baseScore": 1.8,
          "baseSeverity": "LOW",
          "attackVector": "LOCAL",
          "attackComplexity": "LOW",
          "attackRequirements": "PRESENT",
          "privilegesRequired": "NONE",
          "userInteraction": "ACTIVE",
          "vulnConfidentialityImpact": "NONE",
          "vulnIntegrityImpact": "LOW",
          "vulnAvailabilityImpact": "LOW",
          "subConfidentialityImpact": "NONE",
          "subIntegrityImpact": "NONE",
          "subAvailabilityImpact": "NONE",
          "exploitMaturity": "NOT_DEFINED",
          "confidentialityRequirement": "NOT_DEFINED",
          "integrityRequirement": "NOT_DEFINED",
          "availabilityRequirement": "NOT_DEFINED",
          "modifiedAttackVector": "NOT_DEFINED",
          "modifiedAttackComplexity": "NOT_DEFINED",
          "modifiedAttackRequirements": "NOT_DEFINED",
          "modifiedPrivilegesRequired": "NOT_DEFINED",
          "modifiedUserInteraction": "NOT_DEFINED",
          "modifiedVulnConfidentialityImpact": "NOT_DEFINED",
          "modifiedVulnIntegrityImpact": "NOT_DEFINED",
          "modifiedVulnAvailabilityImpact": "NOT_DEFINED",
          "modifiedSubConfidentialityImpact": "NOT_DEFINED",
          "modifiedSubIntegrityImpact": "NOT_DEFINED",
          "modifiedSubAvailabilityImpact": "NOT_DEFINED",
          "Safety": "NOT_DEFINED",
          "Automatable": "NOT_DEFINED",
          "Recovery": "NOT_DEFINED",
          "valueDensity": "NOT_DEFINED",
          "vulnerabilityResponseEffort": "NOT_DEFINED",
          "providerUrgency": "NOT_DEFINED"
        }
      }
    ],
    "cvssMetricV31": [
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        "source": "[email protected]",
        "type": "Primary",
        "cvssData": {
          "version": "3.1",
          "vectorString": "CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:H",
          "baseScore": 6.1,
          "baseSeverity": "MEDIUM",
          "attackVector": "LOCAL",
          "attackComplexity": "LOW",
          "privilegesRequired": "NONE",
          "userInteraction": "REQUIRED",
          "scope": "UNCHANGED",
          "confidentialityImpact": "NONE",
          "integrityImpact": "LOW",
          "availabilityImpact": "HIGH"
        },
        "exploitabilityScore": 1.8,
        "impactScore": 4.2
      }
    ],
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "timestamp": "2026-07-24T12:32:03.340535Z",
          "id": "CVE-2026-56392",
          "options": [
            {
              "exploitation": "none"
            },
            {
              "automatable": "no"
            },
            {
              "technicalImpact": "partial"
            }
          ],
          "role": "CISA Coordinator",
          "version": "2.0.3"
        }
      }
    ]
  },
  "weaknesses": [
    {
      "source": "[email protected]",
      "type": "Secondary",
      "description": [
        {
          "lang": "en",
          "value": "CWE-122"
        }
      ]
    }
  ],
  "configurations": [
    {
      "nodes": [
        {
          "operator": "OR",
          "negate": false,
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  "references": [
    {
      "url": "https://cert.pl/en/posts/2026/07/CVE-2026-56391",
      "source": "[email protected]",
      "tags": [
        "Third Party Advisory"
      ]
    },
    {
      "url": "https://git.savannah.gnu.org/cgit/coreutils.git/",
      "source": "[email protected]",
      "tags": [
        "Product"
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    },
    {
      "url": "https://git.savannah.gnu.org/cgit/coreutils.git/commit/?id=b60a159fdc5bfcf9988d3a4cb6f53abe8ad5d35d",
      "source": "[email protected]",
      "tags": [
        "Patch"
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    }
  ]
}