FKIE_CVE-2026-45785

Vulnerability from fkie_nvd - Published: 2026-07-17 21:17 - Updated: 2026-07-23 18:12
Severity
6.2 (Medium) - CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Summary
OpenMcdf is a fully .NET / C# library to manipulate Compound File Binary File Format files, also known as Structured Storage. In 3.1.3 and earlier, the BST name-lookup loop in DirectoryTree.TryGetDirectoryEntry (OpenMcdf/DirectoryTree.cs:35-46) walks directory entries by repeatedly calling directories.TryGetSibling(child, siblingType, validateColor). A crafted CFB file with cyclic Left/Right sibling links among directory entries, constructed so the per-step BST-order check in TryGetSibling (DirectoryEntries.cs:84-85) is satisfied at every step, drives this while (child is not null) loop forever. There is no cycle detection in TryGetDirectoryEntry, and the bug is reachable from RootStorage.OpenStorage(name), TryOpenStorage(name), OpenStream(name), and TryOpenStream(name), causing an unrecoverable denial of service. This issue is fixed in version 3.1.4.
References
security-advisories@github.comhttps://github.com/openmcdf/openmcdf/commit/c6f82db722bd85db7b0caed3ca1aa374f1e07bc7
security-advisories@github.comhttps://github.com/openmcdf/openmcdf/releases/tag/v3.1.4
security-advisories@github.comhttps://github.com/openmcdf/openmcdf/security/advisories/GHSA-5qwm-7pvp-w988
134c704f-9b21-4f2e-91b3-4a467353bcc0https://github.com/openmcdf/openmcdf/security/advisories/GHSA-5qwm-7pvp-w988
Impacted products
Vendor Product Version
To clipboard 

{
  "affected": [
    {
      "affectedData": [
        {
          "product": "openmcdf",
          "vendor": "openmcdf",
          "versions": [
            {
              "status": "affected",
              "version": "\u003c 3.1.4"
            }
          ]
        }
      ],
      "source": "security-advisories@github.com"
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "OpenMcdf is a fully .NET / C# library to manipulate Compound File Binary File Format files, also known as Structured Storage. In 3.1.3 and earlier, the BST name-lookup loop in DirectoryTree.TryGetDirectoryEntry (OpenMcdf/DirectoryTree.cs:35-46) walks directory entries by repeatedly calling directories.TryGetSibling(child, siblingType, validateColor). A crafted CFB file with cyclic Left/Right sibling links among directory entries, constructed so the per-step BST-order check in TryGetSibling (DirectoryEntries.cs:84-85) is satisfied at every step, drives this while (child is not null) loop forever. There is no cycle detection in TryGetDirectoryEntry, and the bug is reachable from RootStorage.OpenStorage(name), TryOpenStorage(name), OpenStream(name), and TryOpenStream(name), causing an unrecoverable denial of service. This issue is fixed in version 3.1.4."
    }
  ],
  "id": "CVE-2026-45785",
  "lastModified": "2026-07-23T18:12:34.153",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "LOCAL",
          "availabilityImpact": "HIGH",
          "baseScore": 6.2,
          "baseSeverity": "MEDIUM",
          "confidentialityImpact": "NONE",
          "integrityImpact": "NONE",
          "privilegesRequired": "NONE",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
          "version": "3.1"
        },
        "exploitabilityScore": 2.5,
        "impactScore": 3.6,
        "source": "security-advisories@github.com",
        "type": "Secondary"
      }
    ],
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "id": "CVE-2026-45785",
          "options": [
            {
              "exploitation": "poc"
            },
            {
              "automatable": "no"
            },
            {
              "technicalImpact": "partial"
            }
          ],
          "role": "CISA Coordinator",
          "timestamp": "2026-07-21T02:19:43.343147Z",
          "version": "2.0.3"
        }
      }
    ]
  },
  "published": "2026-07-17T21:17:06.650",
  "references": [
    {
      "source": "security-advisories@github.com",
      "url": "https://github.com/openmcdf/openmcdf/commit/c6f82db722bd85db7b0caed3ca1aa374f1e07bc7"
    },
    {
      "source": "security-advisories@github.com",
      "url": "https://github.com/openmcdf/openmcdf/releases/tag/v3.1.4"
    },
    {
      "source": "security-advisories@github.com",
      "url": "https://github.com/openmcdf/openmcdf/security/advisories/GHSA-5qwm-7pvp-w988"
    },
    {
      "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
      "url": "https://github.com/openmcdf/openmcdf/security/advisories/GHSA-5qwm-7pvp-w988"
    }
  ],
  "sourceIdentifier": "security-advisories@github.com",
  "vulnStatus": "Deferred",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-835"
        }
      ],
      "source": "security-advisories@github.com",
      "type": "Secondary"
    }
  ]
}



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