CVE-2026-44018: Docling Unsafe Archive Extraction And XML Vulnerability

MODERATE
Advisory Identifier: GHSA-r3xg-rg9j-67fv
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CVSS 5.5
CWE-409 CWE-776 CWE-611
Published
Advisory Summary

CVE-2026-44018 is a MODERATE (CVSS 5.5) unsafe archive extraction and xml vulnerability (CWE-409: Improper Handling of Highly Compressed Data (Data Amplification)) affecting Docling libraries in the PyPI ecosystem. The issue involves unsafe archive extraction and xml parsing in mets-gbs backend. Remediation is available by upgrading affected packages to version 2.91.0.

CVE-2026-44018 at a Glance

CVE Identifier CVE-2026-44018
GHSA Identifier GHSA-r3xg-rg9j-67fv
Severity MODERATE
CVSS v3.1 Base Score 5.5
CWE Classification CWE-409: Improper Handling of Highly Compressed Data (Data Amplification)
Affected Product Docling
Package Ecosystem PyPI
Published Date
Last Updated

Security Impact

CVSS: 5.5

The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H).

Attack Vector Local (AV:L)
Attack Complexity Low (AC:L)
Privileges Required None (PR:N)
User Interaction Required (UI:R)
Scope Unchanged (S:U)
Confidentiality None (C:N)
Integrity None (I:N)
Availability High (A:H)

How to Fix CVE-2026-44018

To remediate this vulnerability, upgrade all affected Docling dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

docling fixed: 2.91.0 
pip install docling>=2.91.0
Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release: 

pip show docling

How to Check if You Are Affected

To determine whether your Python environment is affected by CVE-2026-44018, inspect your installed packages using pip:

pip show docling

Analyze the terminal output to locate any version of Docling in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 2.91.0), your application is affected.

Note: The pip show docling command checks currently installed packages in your active Python environment.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-409: Improper Handling of Highly Compressed Data (Data Amplification), where the product does not handle or incorrectly handles a compressed input with a very high compression ratio that produces a large output. In Docling, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

### Impact The METS-GBS backend's XML parsing and the input document format detection lacked security controls, enabling: - XML External Entity (XXE) attacks to read local files or cause denial of service - Decompression bombs (zip bombs) to exhaust memory and disk space - Unbounded archive extraction consuming system resources An attacker could craft malicious METS-GBS archives that, when processed, could read sensitive files, exhaust system resources, or cause application crashes. ### Patches Fixed in version 2.91.0. The fix implements: - Secure XML parsing with `resolve_entities=False`, `load_dtd=False`, and `no_network=True` - Configurable limits: 300 MB total extraction size, 10 MB per file, 1000 member count - Cumulative size tracking across all extractions - Early termination when limits are exceeded - Secure format detection of METS-GBS tar archives with `_detect_mets_gbs()` method: maximum file size (10 MB per file), maximum member count (1000 members), and exception handling to gracefully fail when limits are exceeded ### Workarounds Avoid processing METS-GBS archives from untrusted sources. If necessary, pre-validate archives in an isolated environment with resource limits. ### References - Fix release: [v2.91.0](https://github.com/docling-project/docling/releases/tag/v2.91.0)

CVE-2026-44018 Affected Docling Versions

1 component(s)
Fixed Versions:
2.91.0
Product / Package Ecosystem Affected Versions Fixed Version
docling
pypi/docling
PyPI
≥ 2.45.0
< 2.91.0
2.91.0

References

GitHub Advisory / Wiki ADVISORY
https://github.com/docling-project/docling/security/advisories/GHSA-r3xg-rg9j-67fv
NVD — CVE-2026-44018 NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-44018
Docling Source Repository REPOSITORY
https://github.com/docling-project/docling
Docling Release RELEASE
https://github.com/docling-project/docling/releases/tag/v2.91.0
Docling Source Repository REPOSITORY
https://github.com/pypa/advisory-database/tree/main/vulns/docling/PYSEC-2026-2144.yaml

Frequently Asked Questions

What is CVE-2026-44018?
CVE-2026-44018 is a security vulnerability in Docling involving Unsafe Archive Extraction and XML Parsing in METS-GBS Backend under CWE-409: Improper Handling of Highly Compressed Data (Data Amplification).
Which Docling versions are affected?
Affected versions include releases prior to 2.91.0 across affected packages: docling.
What version fixes CVE-2026-44018?
Upgrading to 2.91.0 (or the latest patched release for your respective branch) resolves the vulnerability.
Is docling affected?
Yes, docling is affected in releases prior to 2.91.0. Upgrade your dependency to 2.91.0 or later.
What is the CVSS score of CVE-2026-44018?
CVE-2026-44018 has a CVSS v3.1 base score of 5.5 (MODERATE) with vector string CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H.
What CWE is associated with CVE-2026-44018?
CVE-2026-44018 is classified under CWE-409: Improper Handling of Highly Compressed Data (Data Amplification) (The product does not handle or incorrectly handles a compressed input with a very high compression ratio that produces a large output.).
How can I check PyPI dependencies for CVE-2026-44018?
Run the dependency tree command: 'pip show docling'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
View Raw JSON 
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-r3xg-rg9j-67fv",
  "modified" : "2026-07-21T15:04:20Z",
  "published" : "2026-06-03T21:13:32Z",
  "aliases" : [ "CVE-2026-44018" ],
  "summary" : "Docling: Unsafe Archive Extraction and XML Parsing in METS-GBS Backend",
  "details" : "### Impact\nThe METS-GBS backend's XML parsing and the input document format detection lacked security controls, enabling:\n- XML External Entity (XXE) attacks to read local files or cause denial of service\n- Decompression bombs (zip bombs) to exhaust memory and disk space\n- Unbounded archive extraction consuming system resources\n\nAn attacker could craft malicious METS-GBS archives that, when processed, could read sensitive files, exhaust system resources, or cause application crashes.\n\n### Patches\nFixed in version 2.91.0. The fix implements:\n- Secure XML parsing with `resolve_entities=False`, `load_dtd=False`, and `no_network=True`\n- Configurable limits: 300 MB total extraction size, 10 MB per file, 1000 member count\n- Cumulative size tracking across all extractions\n- Early termination when limits are exceeded\n- Secure format detection of METS-GBS tar archives with `_detect_mets_gbs()` method: maximum file size (10 MB per file), maximum member count (1000 members), and exception handling to gracefully fail when limits are exceeded\n\n### Workarounds\nAvoid processing METS-GBS archives from untrusted sources. If necessary, pre-validate archives in an isolated environment with resource limits.\n\n### References\n- Fix release: [v2.91.0](https://github.com/docling-project/docling/releases/tag/v2.91.0)",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "PyPI",
      "name" : "docling"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "2.45.0"
      }, {
        "fixed" : "2.91.0"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/docling-project/docling/security/advisories/GHSA-r3xg-rg9j-67fv"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-44018"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/docling-project/docling"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/docling-project/docling/releases/tag/v2.91.0"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/pypa/advisory-database/tree/main/vulns/docling/PYSEC-2026-2144.yaml"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-409", "CWE-611", "CWE-776" ],
    "severity" : "MODERATE",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-06-03T21:13:32Z",
    "nvd_published_at" : "2026-06-26T16:16:30Z"
  }
}