CVE-2026-25128: high-severity vulnerability in NaturalIntelligence fast-xml-parser
fast-xml-parser has RangeError DoS Numeric Entities Bug
Published · Updated
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21Vexday Risk Score
No sign of exploitation. No public exploitation artifact known so far.
ssvc Trackcvss 7.5epss 0.6%
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 5.0.9 through 5.3.3, a RangeError vulnerability exists in the numeric entity processing of fast-xml-parser when parsing XML with out-of-range entity code points (e.g., `�` or `�`). This causes the parser to throw an uncaught exception, crashing any application that processes untrusted XML input. Version 5.3.4 fixes the issue.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Affected products
NaturalIntelligence · fast-xml-parserRelated CVEs — NaturalIntelligence fast-xml-parser
In the same product, most dangerous first.
CVE-2023-34104HIGHRegex Injection via Doctype EntitiesEPSS 1.1%CVE-2026-26278HIGHfast-xml-parser affected by DoS through entity expansion in DOCTYPE (no expansion limit)EPSS 0.9%CVE-2024-41818HIGHReDOS at currency parsing fast-xml-parserEPSS 0.8%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%