CVE-2026-26278highCWE-776

CVE-2026-26278: fallo de gravedad alta en NaturalIntelligence fast-xml-parser

fast-xml-parser affected by DoS through entity expansion in DOCTYPE (no expansion limit)

Publicada el · Actualizada el

Seguir esta CVE+ Monitorear fast-xml-parser+ Monitorear fast-xml-parser

Aviso por correo cuando entre en el KEV, tenga PoC pública o suba de nota.

21Vexday Risk Score

Sin señal de explotación. Ningún artefacto público de explotación conocido hasta ahora.

ssvc Trackcvss 7.5epss 0.9%
fast-xml-parser allows users to validate XML, parse XML to JS object, or build XML from JS object without C/C++ based libraries and no callback. In versions 4.1.3 through 5.3.5, the XML parser can be forced to do an unlimited amount of entity expansion. With a very small XML input, it’s possible to make the parser spend seconds or even minutes processing a single request, effectively freezing the application. Version 5.3.6 fixes the issue. As a workaround, avoid using DOCTYPE parsing by `processEntities: false` option.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Productos afectados
NaturalIntelligence · fast-xml-parser
CVEs relacionadas — NaturalIntelligence fast-xml-parser

En el mismo producto, de las más peligrosas a las menos.

CVE-2023-34104HIGHRegex Injection via Doctype EntitiesEPSS 1.1%CVE-2024-41818HIGHReDOS at currency parsing fast-xml-parserEPSS 0.8%CVE-2026-25128HIGHfast-xml-parser has RangeError DoS Numeric Entities BugEPSS 0.6%CVE-2026-33036HIGHfast-xml-parser affected by numeric entity expansion bypassing all entity expansion limits (incomplete fix for CVE-2026-26278)EPSS 0.6%CVE-2026-27942LOWfast-xml-parser has stack overflow in XMLBuilder with preserveOrderEPSS 0.5%CVE-2026-25896CRITICALfast-xml-parser has an entity encoding bypass via regex injection in DOCTYPE entity namesEPSS 0.5%