CVE-2026-44020 — docling
HIGHCVE-2026-44020 is a high-severity (CVSS 7.5) CWE-776 vulnerability in docling. A fix is available for docling — see the affected versions and patch details below.
Docling: Unsafe XML Entity Expansion in USPTO Patent Backend
Exploitation Status
No confirmed exploitation observed yet
- CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
- CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.
Exploitation and automatability from CISA’s SSVC triage for CVE-2026-44020.
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
How urgent is this, really
CVE-2026-44020 plotted by exploitation likelihood (EPSS) against impact (CVSS). The shaded corner — EPSS 50%+ and CVSS 7.0+ — is where this CVE doesn't sit, though severity or exploitability alone can still warrant action.
Where this sits among everything scored
Of 379,145 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Real counts from FIRST.org, not a sample — log-scaled since the landscape is heavily right-skewed.
Real-World Exposure
doclingReal-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
Impact
The USPTO patent XML parser used the standard xml.sax.parseString() without protection against XML External Entity (XXE) attacks. An attacker could craft malicious USPTO patent XML files with external entity references that could:
- Read arbitrary files from the server filesystem
- Perform Server-Side Request Forgery (SSRF) attacks
- Cause denial of service through entity expansion (Billion Laughs attack)
The vulnerability affects three USPTO patent format parsers: ICE (v4.x), Grant v2.5, and Application v1.x.
Patches
Fixed in version 2.74.0. The parser now uses defusedxml.sax.make_parser() with secure configuration that blocks external entity resolution (feature_external_ges=False, feature_external_pes=False) while allowing DTD declarations required by USPTO files. This prevents XXE attacks while maintaining compatibility with the USPTO XML format.
Workarounds
Avoid processing USPTO patent XML files from untrusted sources. Implement resource limits (memory, CPU time) when processing patent documents.
References
- Fix release: v2.74.0
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐍PyPI | docling | ≥ 2.13.0&&< 2.74.0 | 2.74.0pip install --upgrade 'docling==2.74.0' |
Detection & 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 2.74.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-44020 is resolved across your whole dependency graph.
Workarounds
Restrict outbound requests from the affected component to an allowlist of hosts, block access to link-local and internal address ranges at the network layer, and require authentication on internal services so a forged request cannot reach them unauthenticated.
How O3 protects you
O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like CVE-2026-44020 can be triaged on real exposure rather than presence alone.
Tailored to CVE-2026-44020. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
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.
This is an Important vulnerability in docling, as shipped with Red Hat OpenShift AI, due to an XML External Entity (XXE) flaw in its USPTO patent XML parser. An attacker could exploit this by providing specially crafted XML files, leading to unauthorized access to local files, Server-Side Request Forgery (SSRF), or…
| Product | Fixed in | Advisory |
|---|---|---|
| Red Hat OpenShift AI 3.4 | rhoai/odh-autorag-rhel9:1786612637 | RHSA-2026:60520 |
Frequently Asked Questions
Is CVE-2026-44020 in your dependencies?
O3 Security finds CVE-2026-44020 across PyPI dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.