NaturalIntelligence fast-xml-parser vulnerabilities

Latest NaturalIntelligence fast-xml-parser CVEs

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1. CVE-2026-126066 fast-xml-parser: Quadratic CPU consumption scanning unterminated stop-node tags

   Published 2026-11-10

   Low·CVSS 3.7 EPSS 0.46%

   fast-xml-parser allows users to process XML from JS object without C/C++ based libraries or callbacks. Prior to 5.12.0, when the non-default stopNodes option is enabled, readStopNodeData() in OrderedObjParser.js calls readTagExp() for each less-than character in an unterminated s...

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

   Published 2026-08-13

   High·CVSS 8.7 EPSS 0.51%

   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 ad...

3. CVE-2026-41650 fast-xml-parser XMLBuilder: XML Comment and CDATA Injection via Unescaped Delimiters

   Published 2026-05-07

   Medium·CVSS 6.1 EPSS 0.24%

   fast-xml-parser allows users to process XML from JS object without C/C++ based libraries or callbacks. Prior to version 5.7.0, XMLBuilder does not escape the "-->" sequence in comment content or the "]]>" sequence in CDATA sections when building XML from JavaScript objects. This...

4. CVE-2026-33349 fast-xml-parser: Entity Expansion Limits Bypassed When Set to Zero Due to JavaScript Falsy Evaluation

   Published 2026-03-24

   Medium·CVSS 5.9 EPSS 0.48%

   fast-xml-parser allows users to process XML from JS object without C/C++ based libraries or callbacks. From version 4.0.0-beta.3 to before version 5.5.7, the DocTypeReader in fast-xml-parser uses JavaScript truthy checks to evaluate maxEntityCount and maxEntitySize configuration...

5. CVE-2026-33036 fast-xml-parser affected by numeric entity expansion bypassing all entity expansion limits (incomplete fix for CVE-2026-26278)

   Published 2026-03-20

   High·CVSS 7.5 EPSS 0.61%

   fast-xml-parser allows users to process XML from JS object without C/C++ based libraries or callbacks. Versions 4.0.0-beta.3 through 5.5.5 contain a bypass vulnerability where numeric character references (&#NNN;, &#xHH;) and standard XML entities completely evade the entity expa...

6. CVE-2026-27942 fast-xml-parser has stack overflow in XMLBuilder with preserveOrder

   Published 2026-02-26

   Low·CVSS 2.7 EPSS 0.54%

   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. Prior to version 5.3.8, the application crashes with stack overflow when user use XML builder with preserveOrder:true. Version 5.3.8 fi...

7. CVE-2026-25896 fast-xml-parser has an entity encoding bypass via regex injection in DOCTYPE entity names

   Published 2026-02-20

   Critical·CVSS 9.3 EPSS 0.53%

   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. From 4.1.3to before 5.3.5, a dot (.) in a DOCTYPE entity name is treated as a regex wildcard during entity replacement, allowing an att...

8. CVE-2026-26278 fast-xml-parser affected by DoS through entity expansion in DOCTYPE (no expansion limit)

   Published 2026-02-19

   High·CVSS 7.5 EPSS 0.94%

   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 inpu...

9. CVE-2026-25128 fast-xml-parser has RangeError DoS Numeric Entities Bug

   Published 2026-01-30

   High·CVSS 7.5 EPSS 0.61%

   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...

10. CVE-2024-41818 ReDOS at currency parsing fast-xml-parser

    Published 2024-07-29

    High·CVSS 7.5 EPSS 0.83%

    fast-xml-parser is an open source, pure javascript xml parser. a ReDOS exists on currency.js. This vulnerability is fixed in 4.4.1.

11. CVE-2023-34104 Regex Injection via Doctype Entities

    Published 2023-06-06

    High·CVSS 7.5 EPSS 1.1%

    fast-xml-parser is an open source, pure javascript xml parser. fast-xml-parser allows special characters in entity names, which are not escaped or sanitized. Since the entity name is used for creating a regex for searching and replacing entities in the XML body, an attacker can a...

Sources: CVE.org, NVD, CISA KEV, FIRST EPSS, OSV and public exploit-reference metadata. Product matching comes from the published CVE records. A proof-of-concept means public code exists; it is not evidence of exploitation.