CVE-2026-26197

Full vulnerability record from the local CVENow database.

Description

HDF5 is a high-performance library and a file format specification that implements the HDF5 data model. If a file is corrupted such that an array datatype's size, the number of elements, and the element size are not in agreement it can trigger an out of bounds read. The array datatype stores the full size of the datatype (`dt->shared->size`) separately from the number of elements (`dt->shared->u.array.nelem`) and the element size (`dt->shared->parent->shared->size`). If any one of these are corrupted so that they don't align with the others (element size * nelem = full size), it can lead to an out of bounds read. Depending on what is corrupted, it can alter the type of out of bounds read triggered. The vulnerability is present only in files that have been maliciously altered, as its generally not possible to independently alter the full size of the datatype, the element count and the element size. As such, this is only present if a malicious actor is altering files, and won't appear in regular usage.

Severity

MEDIUM

CVSS score

5.9 (v4.0)

Vulnerability status

Analyzed

Source identifier

[email protected]

Published

2026-07-20 16:16:57.400000

Last modified

2026-10-24 20:10:00.137000

View original CVE JSON

{
  "id": "CVE-2026-26197",
  "sourceIdentifier": "[email protected]",
  "published": "2026-07-20T16:16:57.400",
  "lastModified": "2026-10-24T20:10:00.137",
  "vulnStatus": "Analyzed",
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "HDF5 is a high-performance library and a file format specification that implements the HDF5 data model. If a file is corrupted such that an array datatype's size, the number of elements, and the element size  are not in agreement it can trigger an out of bounds read. The array datatype stores the full size of the datatype (`dt->shared->size`) separately from the number of elements (`dt->shared->u.array.nelem`) and the element size (`dt->shared->parent->shared->size`). If any one of these are corrupted so that they don't align with the others (element size * nelem = full size), it can lead to an out of bounds read. Depending on what is corrupted, it can alter the type of out of bounds read triggered. The vulnerability is present only in files that have been maliciously altered, as its generally not possible to independently alter the full size of the datatype, the element count and the element size. As such, this is only present if a malicious actor is altering files, and won't appear in regular usage."
    },
    {
      "lang": "es",
      "value": "HDF5 es una biblioteca de alto rendimiento y una especificación de formato de archivo que implementa el modelo de datos HDF5. Si un archivo está corrupto de tal manera que el tamaño de un tipo de datos de array, el número de elementos y el tamaño del elemento no concuerdan, puede desencadenar una lectura fuera de límites. El tipo de datos de array almacena el tamaño completo del tipo de datos (’dt  ->  shared  ->  size’) por separado del número de elementos (’dt  ->  shared  ->  u.array.nelem’) y el tamaño del elemento (’dt  ->  shared  ->  parent  ->  shared  ->  size’). Si cualquiera de estos está corrupto de modo que no se alinea con los demás (tamaño del elemento * nelem = tamaño completo), puede llevar a una lectura fuera de límites. Dependiendo de lo que esté corrupto, puede alterar el tipo de lectura fuera de límites desencadenada. La vulnerabilidad está presente solo en archivos que han sido alterados maliciosamente, ya que generalmente no es posible alterar independientemente el tamaño completo del tipo de datos, el recuento de elementos y el tamaño del elemento. Como tal, esto solo está presente si un actor malicioso está alterando archivos, y no aparecerá en el uso regular."
    }
  ],
  "affected": [
    {
      "source": "[email protected]",
      "affectedData": [
        {
          "vendor": "HDFGroup",
          "product": "hdf5",
          "versions": [
            {
              "version": "< 2.0.0",
              "status": "affected"
            }
          ]
        }
      ]
    }
  ],
  "metrics": {
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        "source": "[email protected]",
        "type": "Secondary",
        "cvssData": {
          "version": "4.0",
          "vectorString": "CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:A/VC:N/VI:N/VA:H/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": 5.9,
          "baseSeverity": "MEDIUM",
          "attackVector": "NETWORK",
          "attackComplexity": "HIGH",
          "attackRequirements": "PRESENT",
          "privilegesRequired": "NONE",
          "userInteraction": "ACTIVE",
          "vulnConfidentialityImpact": "NONE",
          "vulnIntegrityImpact": "NONE",
          "vulnAvailabilityImpact": "HIGH",
          "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"
        }
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    "cvssMetricV31": [
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        "source": "[email protected]",
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          "attackComplexity": "LOW",
          "privilegesRequired": "NONE",
          "userInteraction": "NONE",
          "scope": "UNCHANGED",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "NONE",
          "availabilityImpact": "NONE"
        },
        "exploitabilityScore": 3.9,
        "impactScore": 3.6
      }
    ],
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "timestamp": "2026-07-20T15:32:48.424585Z",
          "id": "CVE-2026-26197",
          "options": [
            {
              "exploitation": "poc"
            },
            {
              "automatable": "no"
            },
            {
              "technicalImpact": "partial"
            }
          ],
          "role": "CISA Coordinator",
          "version": "2.0.3"
        }
      }
    ]
  },
  "weaknesses": [
    {
      "source": "[email protected]",
      "type": "Primary",
      "description": [
        {
          "lang": "en",
          "value": "CWE-125"
        }
      ]
    }
  ],
  "configurations": [
    {
      "nodes": [
        {
          "operator": "OR",
          "negate": false,
          "cpeMatch": [
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              "vulnerable": true,
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  "references": [
    {
      "url": "https://github.com/HDFGroup/hdf5/security/advisories/GHSA-gh44-7wpq-622f",
      "source": "[email protected]",
      "tags": [
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        "Vendor Advisory"
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    },
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}