CVE-2026-44020

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.

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.

### 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](https://github.com/docling-project/docling/releases/tag/v2.74.0)

Docling simplifica el procesamiento de documentos al analizar diversos formatos y al proporcionar integraciones con el ecosistema de IA generativa. Desde la versión 2.13.0 hasta la 2.74.0, el analizador XML de patentes de la USPTO utilizó la función estándar xml.sax.parseString() sin protección contra ataques de entidad externa XML (XXE). Un atacante podría crear archivos XML de patentes de la USPTO maliciosos con referencias a entidades externas que podrían leer archivos arbitrarios del sistema de archivos del servidor, realizar ataques de falsificación de petición del lado del servidor (SSRF) o causar denegación de servicio a través de la expansión de entidades (ataque Billion Laughs). La vulnerabilidad afecta a tres analizadores de formato de patentes de la USPTO: ICE (v4.x), Grant v2.5 y Application v1.x. Esta vulnerabilidad está corregida en la versión 2.74.0.