CVE-2026-24009 is a high-severity (CVSS 8.1) Deserialization of Untrusted Data vulnerability in docling-core. O3 Security confirms whether CVE-2026-24009 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
Docling Core vulnerable to Remote Code Execution via unsafe PyYAML usage
Real-World Exposure
docling-coreReal-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
Docling Core (or docling-core) is a library that defines core data types and transformations in the document processing application Docling. A PyYAML-related Remote Code Execution (RCE) vulnerability, namely CVE-2020-14343, is exposed in docling-core starting in version 2.21.0 and prior to version 2.48.4, specifically only if the application uses pyyaml prior to version 5.4 and invokes docling_core.types.doc.DoclingDocument.load_from_yaml() passing it untrusted YAML data. The vulnerability has been patched in docling-core version 2.48.4. The fix mitigates the issue by switching PyYAML deserialization from yaml.FullLoader to yaml.SafeLoader, ensuring that untrusted data cannot trigger code execution. Users who cannot immediately upgrade docling-core can alternatively ensure that the installed version of PyYAML is 5.4 or greater.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐍PyPI | docling-core | ≥ 2.21.0&&< 2.48.4 | 2.48.4 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for docling-core. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update docling-core to 2.48.4 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-24009 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether CVE-2026-24009 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to CVE-2026-24009. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2026-24009 in your dependencies?
O3 detects CVE-2026-24009 across PyPI dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.