Summary
Docling: METS-GBS archive member limit enforced after full member enumeration (memory exhaustion during format detection)
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 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.
Details
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.
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 allowed_formats is applied, so the allocation happens even when METS-GBS is not an allowed format.
This 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.
Workarounds
Upgrade to 2.131.0. For older versions:
Reject gzip or tar inputs before they reach docling when METS-GBS support is not needed, and run conversions of untrusted input with memory limits.
Impact
Memory exhaustion of the converting process, proportional to the size of the input archive. Confidentiality and integrity are not affected.
The application allocates resources such as memory, threads, or file descriptors based on untrusted input without enforcing a cap. Typical impact: resource exhaustion leading to denial of service.
CVE-2026-105747 has a CVSS score of 4.3 (Medium). The vector is network-reachable, no privileges required, and user interaction required. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (2.131.0); upgrading removes the vulnerable code path.
Affected versions
Security releases
Kodem intelligence
Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.
Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter. Kodem's runtime-powered SCA identifies whether this CVE is reachable in your applications.
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Fixed in docling 2.131.0 by #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.
Frequently Asked Questions
- What is CVE-2026-105747? CVE-2026-105747 is a medium-severity allocation of resources without limits or throttling vulnerability in docling (pip), affecting versions >= 2.45.0, < 2.131.0. It is fixed in 2.131.0. The application allocates resources such as memory, threads, or file descriptors based on untrusted input without enforcing a cap.
- How severe is CVE-2026-105747? CVE-2026-105747 has a CVSS score of 4.3 (Medium). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
- Which packages are affected by CVE-2026-105747?
docling(pip) (versions >= 2.45.0, < 2.131.0)docling-slim(pip) (versions >= 2.92.0, < 2.131.0)
- Is there a fix for CVE-2026-105747? Yes. CVE-2026-105747 is fixed in 2.131.0. Upgrade to this version or later.
- Is CVE-2026-105747 exploitable, and should I be worried? Whether CVE-2026-105747 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
- What actually determines whether CVE-2026-105747 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
- How do I fix CVE-2026-105747?
- Upgrade
doclingto 2.131.0 or later - Upgrade
docling-slimto 2.131.0 or later
- Upgrade