Docling: METS-GBS archive member limit enforced after full member enumeration (memory exhaustion during format detection)

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS

4.3 · CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:L

EPSS

• CVE-2026-105747: 0.30% estimated exploitation activity in the next 30 days; percentile 22.65 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

Summary When 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 maxmembercount 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. Details docling/datamodel/document.py (format detection) and docling/backend/metsgbsbackend.py both iterate tar.getmembers() and count members inside the loop. getmembers() reads every header up front. Measured 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 allowedformats is applied, so the allocation happens even when METS-GBS is not an allowed format. This check was introduced by the fix for…

Published by the source

6 Oct 2026, 13:41 UTC

Last modified by the source

15 Oct 2026, 14:56 UTC

Source last checked

26 Oct 2026, 13:55 UTC

1. Revision 3 · amended · 26 Oct 2026

   Amended from ghsa record GHSA-3cr3-8m4c-fpxw

2. Revision 2 · amended · 24 Oct 2026

   Amended from osv record GHSA-3cr3-8m4c-fpxw

3. Revision 1 · created · 23 Oct 2026

   Published from ghsa record GHSA-3cr3-8m4c-fpxw

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# Patch Next advisory brief: CVE-2026-105747

Advisory: Docling: METS-GBS archive member limit enforced after full member enumeration (memory exhaustion during format detection)
IDs: CVE-2026-105747, GHSA-3cr3-8m4c-fpxw
Record: https://patchnext.com/advisories/cve-2026-105747 (revision 3, source checked 26 Oct 2026, 13:55 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Medium (CVSS 4.3)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: docling-slim 2.131.0; docling 2.131.0. A vendor fix does not mean a deployment is fixed.

## Affected components
- PyPI docling-slim: affected >= 2.92.0, < 2.131.0; fixed in 2.131.0
- PyPI docling: affected >= 2.45.0, < 2.131.0; fixed in 2.131.0

## Suggested inspection (read-only)
- `python -m pip show docling-slim`: prints the installed version. Run with the environment that serves production active.
- `python -m pip show docling`: prints the installed version. Run with the environment that serves production active.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on docling-slim, docling.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-3cr3-8m4c-fpxw (GitHub-reviewed advisory GHSA-3cr3-8m4c-fpxw lists affected ranges: PyPI docling >=2.45.0 =2.92.0 <2.131.0)
- Verified: https://osv.dev/vulnerability/GHSA-3cr3-8m4c-fpxw (OSV record GHSA-3cr3-8m4c-fpxw lists affected ranges: PyPI docling >=2.45.0 =2.92.0 <2.131.0 (fixed))

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