CVE-2026-73569fast-xml-parser: Repeated DOCTYPE declarations reset entity expansion limits

Descripción

fast-xml-parser allows users to process XML from JS object without C/C++ based libraries or callbacks. From 5.9.3 until 5.10.1, src/xmlparser/OrderedObjParser.js processes multiple DOCTYPE declarations within a single XML document and passes each declaration's entities through addInputEntities(). addInputEntities() resets maxTotalExpansions and maxExpandedLength every time it is called, allowing additional DOCTYPE declarations to repeatedly reset the configured entity-expansion limits during one parse operation. A crafted XML document can then cause excessive CPU use, event-loop blocking, memory exhaustion, and process termination. This issue is fixed in version 5.10.1.

Datos: CVE.org, NVD, CISA KEV, FIRST EPSS, Ubuntu. Se publican tal como los indican las fuentes, en inglés.

Productos y versiones afectados

Referencias y parches

• https://github.com/NaturalIntelligence/fast-xml-parser/security/advisories/GHSA-8r6m-32jq-jx6q
• https://github.com/NaturalIntelligence/fast-xml-parser/commit/4e546e03987662de5495d050b5fba26bea65383f
• https://github.com/NaturalIntelligence/fast-xml-parser/releases/tag/v5.10.1