Docling: Unbounded table rowspan/colspan in HTML, JATS, ODS and BoxNote backends causes CPU/memory exhaustionGHSA-cgc7-9qp3-86m3
MEDIUMFix: docling-project/docling#4414GHSA-cgc7-9qp3-86m3 is a medium-severity (CVSS 6.5) Uncontrolled Resource Consumption vulnerability in docling. A fix is available for docling — see the affected versions and patch details below.
Exploitation Status
Proof-of-concept exploit code exists
- CISA’s SSVC triage found public proof-of-concept exploit code for this CVE, though no confirmed active exploitation.
Exploitation and automatability from CISA’s SSVC triage for GHSA-cgc7-9qp3-86m3.
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
GHSA-cgc7-9qp3-86m3 by exploitation likelihood (EPSS) against impact (CVSS). Outside the shaded patch-first corner.
Where this sits among everything scored
Of 394,803 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Counts from FIRST.org, log-scaled.
Real-World Exposure
docling🐍docling-slimReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects PyPI packages — download data is not available via public APIs for these ecosystems.
Description
Summary
The HTML, JATS, ODS (OpenDocument spreadsheet) and BoxNote backends accept table rowspan / colspan values without an upper bound. A few bytes of input, such as <td rowspan="100000000">, make docling run loops proportional to the declared span and allocate a table grid of the declared size. The result is CPU and memory exhaustion.
Details
docling/backend/html_backend.py(_get_cell_spans) parses span attributes with no upper limit. The cell-filling loop then iteratesrow_span × col_spantimes.docling/backend/jats_backend.pyanddocling/backend/boxnote_backend.pyfill their tables the same way.- The OpenDocument spreadsheet path scans the declared span range.
- Export (for example
export_to_markdown()) materialises the full grid throughTableData.gridin docling-core.
document_timeout does not bound this. It is checked between pipeline stages, and these backends convert the whole document in a single call. max_file_size and max_num_pages do not help because the payload is tiny.
Measured on 2.130.0: a 54-byte HTML file with rowspan="1e8" takes about 4.4 s of CPU, and the time grows linearly with the value. A 52-byte file with colspan="3000000" takes about 23 s and reaches 4.5 GB peak memory during Markdown export.
Impact
Denial of service of the converting process from a very small input document. Confidentiality and integrity are not affected.
Proof of concept
<table><tr><td colspan="3000000">x</td></tr></table>
from docling.document_converter import DocumentConverter
DocumentConverter().convert("span.html").document.export_to_markdown()
Patches
Fixed in docling 2.131.0 by #4414. Table spans are clamped to the HTML limits (colspan 1000, rowspan 65534) and to the actual size of the table in the HTML, JATS, BoxNote and OpenDocument spreadsheet backends, so conversion time and memory grow with the real table only.
Workarounds
Upgrade to 2.131.0. For older versions:
Run conversions of untrusted documents in a separate process with memory and CPU-time limits, or restrict allowed_formats to formats that are not affected.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐍PyPI | docling | ≥ 2.0.0&&< 2.131.0 | 2.131.0pip install --upgrade 'docling==2.131.0' |
| 🐍PyPI | docling-slim | ≥ 2.92.0&&< 2.131.0 | 2.131.0pip install --upgrade 'docling-slim==2.131.0' |
Affected Products
doclingdoclingDetection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for docling, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update docling to 2.131.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-cgc7-9qp3-86m3 is resolved across your whole dependency graph.
Workarounds
Cap what an attacker can consume: apply request size, rate and timeout limits in front of the affected component, and run it with memory and CPU limits so exhaustion degrades one worker rather than the whole service.
Fixing This On Your OS
If you run this on a Linux distribution, patch through your package manager against the distro's own security advisory below — it tracks the exact backported fix for your release, which can ship on a different timeline (and sometimes a different severity) than the upstream project.
Red Hat rates this docling flaw as having MODERATE security impact (CVSS 3.1 score 6.5, AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H), consistent with the upstream assessment. A denial of service flaw was found in the docling document conversion library, which Red Hat ships bundled in Red Hat OpenShift AI (RHOAI) and…
Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base, or stability. In particular, the docling document_timeout setting does not interrupt the vulnerable backend conversion call and therefore does not prevent the resource exhaustion. The upstream docling project has fixed this issue in version 2.131.0.Source: Red Hat security advisory for GHSA-cgc7-9qp3-86m3 (CC BY 4.0)
Frequently Asked Questions
Is GHSA-cgc7-9qp3-86m3 in your dependencies?
Find it across PyPI, including transitive dependencies.