CVE-2026-120756

Full vulnerability record from the local CVENow database.

Description

HDF5 through 2.2.0 contains a heap buffer over-read vulnerability in H5O__chunk_deserialize() in src/H5Ocache.c. When decoding object header messages, the declared message size is checked against the end of the chunk image before the remainder of the message header (flags, and for version 2 object headers, the optional creation index) has been decoded. Because the message body begins after these fields, a message can start up to four bytes further into the chunk than the size check accounts for. A crafted HDF5 file can declare a message size that passes the check but extends past the end of the chunk image, causing the message’s decode callback, for example H5O__mtime_new_decode() in src/H5Omtime.c, to read beyond the heap allocation. The flaw is reachable during H5Fopen() on a crafted file. An attacker who can get a user or application to open a malicious file can cause a denial of service or limited disclosure of process memory.

Severity

LOW

CVSS score

1.9 (v4.0)

Vulnerability status

Awaiting Analysis

Source identifier

0253b833-3e77-4dfe-9d57-17db1a2f0a74

Published

2026-11-03 16:17:22.940000

Last modified

2026-11-03 16:30:17.150000

View original CVE JSON

{
  "id": "CVE-2026-120756",
  "sourceIdentifier": "0253b833-3e77-4dfe-9d57-17db1a2f0a74",
  "published": "2026-11-03T16:17:22.940",
  "lastModified": "2026-11-03T16:30:17.150",
  "vulnStatus": "Awaiting Analysis",
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "HDF5 through 2.2.0 contains a heap buffer over-read vulnerability in H5O__chunk_deserialize() in src/H5Ocache.c. When decoding object header messages, the declared message size is checked against the end of the chunk image before the remainder of the message header (flags, and for version 2 object headers, the optional creation index) has been decoded. Because the message body begins after these fields, a message can start up to four bytes further into the chunk than the size check accounts for. A crafted HDF5 file can declare a message size that passes the check but extends past the end of the chunk image, causing the message’s decode callback, for example H5O__mtime_new_decode() in src/H5Omtime.c, to read beyond the heap allocation. The flaw is reachable during H5Fopen() on a crafted file. An attacker who can get a user or application to open a malicious file can cause a denial of service or limited disclosure of process memory."
    }
  ],
  "affected": [
    {
      "source": "0253b833-3e77-4dfe-9d57-17db1a2f0a74",
      "affectedData": [
        {
          "vendor": "The HDF Group",
          "product": "HDF5",
          "defaultStatus": "unaffected",
          "modules": [
            "Object Header"
          ],
          "versions": [
            {
              "version": "< 2.3.0",
              "status": "affected"
            }
          ]
        }
      ]
    }
  ],
  "metrics": {
    "cvssMetricV40": [
      {
        "source": "0253b833-3e77-4dfe-9d57-17db1a2f0a74",
        "type": "Secondary",
        "cvssData": {
          "version": "4.0",
          "vectorString": "CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:L/VI:N/VA:L/SC:N/SI:N/SA:N/E:P/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": 1.9,
          "baseSeverity": "LOW",
          "attackVector": "LOCAL",
          "attackComplexity": "LOW",
          "attackRequirements": "NONE",
          "privilegesRequired": "NONE",
          "userInteraction": "PASSIVE",
          "vulnConfidentialityImpact": "LOW",
          "vulnIntegrityImpact": "NONE",
          "vulnAvailabilityImpact": "LOW",
          "subConfidentialityImpact": "NONE",
          "subIntegrityImpact": "NONE",
          "subAvailabilityImpact": "NONE",
          "exploitMaturity": "PROOF_OF_CONCEPT",
          "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"
        }
      }
    ]
  },
  "weaknesses": [
    {
      "source": "0253b833-3e77-4dfe-9d57-17db1a2f0a74",
      "type": "Secondary",
      "description": [
        {
          "lang": "en",
          "value": "CWE-125"
        }
      ]
    }
  ],
  "references": [
    {
      "url": "https://github.com/HDFGroup/hdf5/issues/6401",
      "source": "0253b833-3e77-4dfe-9d57-17db1a2f0a74"
    },
    {
      "url": "https://github.com/HDFGroup/hdf5/pull/6589",
      "source": "0253b833-3e77-4dfe-9d57-17db1a2f0a74"
    }
  ]
}