CVE-2026-105747: Docling Remote Code Execution Vulnerability

{
  "schema_version" : "1.4.0",
  "id" : "GHSA-3cr3-8m4c-fpxw",
  "modified" : "2026-10-06T13:43:19Z",
  "published" : "2026-10-06T13:41:16Z",
  "aliases" : [ "CVE-2026-105747" ],
  "summary" : "Docling: METS-GBS archive member limit enforced after full member enumeration (memory exhaustion during format detection)",
  "details" : "### Summary\n\nWhen docling detects the input format of a gzip-compressed tar archive (METS-GBS), and later when the METS-GBS backend opens it, it calls `tarfile.TarFile.getmembers()`. That builds the full member list in memory before the `max_member_count` limit is checked. A small archive with a very large number of empty members therefore makes docling allocate memory in proportion to the member count, and the limit has no effect.\n\n### Details\n\n`docling/datamodel/document.py` (format detection) and `docling/backend/mets_gbs_backend.py` both iterate `tar.getmembers()` and count members inside the loop. `getmembers()` reads every header up front.\n\nMeasured on Python 3.12: an archive of 1,000,000 empty members compresses to about 6.2 MB and makes `getmembers()` hold about 408 MB (about 66 times the input size). Format detection runs for any `application/gzip` input before `allowed_formats` is applied, so the allocation happens even when METS-GBS is not an allowed format.\n\nThis check was introduced by the fix for CVE-2026-44018 (GHSA-r3xg-rg9j-67fv) in 2.91.0. The eager enumeration it relies on has been there since METS-GBS detection was added in 2.45.0.\n\n### Impact\n\nMemory exhaustion of the converting process, proportional to the size of the input archive. Confidentiality and integrity are not affected.\n\n### Patches\n\nFixed in docling 2.131.0 by [#4412](https://github.com/docling-project/docling/pull/4412). Format detection and the METS-GBS backend now read archive members one at a time and stop as soon as `max_member_count` is exceeded, including when looking up page files.\n\n### Workarounds\n\nUpgrade to 2.131.0. For older versions:\n\nReject gzip or tar inputs before they reach docling when METS-GBS support is not needed, and run conversions of untrusted input with memory limits.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:L"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "PyPI",
      "name" : "docling"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "2.45.0"
      }, {
        "fixed" : "2.131.0"
      } ]
    } ]
  }, {
    "package" : {
      "ecosystem" : "PyPI",
      "name" : "docling-slim"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "2.92.0"
      }, {
        "fixed" : "2.131.0"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/docling-project/docling/security/advisories/GHSA-3cr3-8m4c-fpxw"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-105747"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/docling-project/docling/pull/4412"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/docling-project/docling/commit/ebae65cd71c37c88b36185b406a449b92d8f7ffa"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/docling-project/docling"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/docling-project/docling/releases/tag/v2.131.0"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-409", "CWE-770" ],
    "severity" : "MODERATE",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-10-06T13:41:16Z",
    "nvd_published_at" : null
  }
}