---
id: CVE-2026-31248
aliases:
  - GHSA-9f4q-q82q-4359
  - PYSEC-2026-2454
title: Docling's METS GBS backend is vulnerable to XML Entity Expansion (XXE) attacks
summary: Docling's METS GBS backend is vulnerable to XML Entity Expansion (XXE) attacks
severity: high
cvss: 7.5
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H'
vendor: docling
product: docling
ecosystem: pip
affected:
  - docling <= 2.61.0
published: '2026-05-11'
updated: '2026-07-13'
source: OSV
sourceUrl: 'https://osv.dev/vulnerability/GHSA-9f4q-q82q-4359'
references:
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-31248'
  - url: 'https://github.com/docling-project/docling'
  - url: 'https://www.notion.so/CVE-2026-31248-35d1e1393188818585b2ce3b9ce24686'
tags:
  - osv
  - pip
epss: 0.00488
epssPercentile: 0.39334
ingestedAt: '2026-07-13T18:57:55.881Z'
---

## Overview

Docling's METS GBS backend is vulnerable to XML Entity Expansion (XXE) attacks thru 2.61.0. The backend extracts and validates XML files from .tar.gz archives using etree.fromstring() without disabling entity resolution. An attacker can craft a malicious XML file with nested entity definitions (XML Bomb) and package it into a .tar.gz archive. When processed by Docling, the exponential expansion of entities during XML parsing leads to excessive resource consumption, resulting in a denial of service (DoS) condition on the system running the Docling parser.

## Affected packages

- `docling <= 2.61.0`

## Remediation

Refer to the advisory for the patched release.