In short
- CVE-2026-44020 is a HIGH (CVSS 7.5) vulnerability affecting docling, docling (docling).
- Chance of exploitation in the next 30 days (EPSS): 0.60%, higher than 48.8% of all vulnerabilities.
- Fix: update to 2.74.0 or later.
| Package | Affected versions | Patched versions |
|---|
| docling PyPI | ≥ 2.13.0, < 2.74.0
| 2.74.0
|
| docling | ≥ 2.13.0, < 2.74.0
| 2.74.0
|
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
NVD description
Docling simplifies document processing by parsing diverse formats and providing integrations with the generative AI ecosystem. From 2.13.0 until 2.74.0, 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, or 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. This vulnerability is fixed in 2.74.0.
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