Vulnerability Details CVE-2026-25896
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 attacker to shadow built-in XML entities (<, >, &, ", ') with arbitrary values. This bypasses entity encoding and leads to XSS when parsed output is rendered. This vulnerability is fixed in 5.3.5.
Exploit prediction scoring system (EPSS) score
EPSS Score 0.0
EPSS Ranking 12.0%
CVSS Severity
CVSS v3 Score 9.3
References
- https://github.com/NaturalIntelligence/fast-xml-parser/commit/943ef0eb1b2d3284e72dd74f44a042ee9f07026e
- https://github.com/NaturalIntelligence/fast-xml-parser/commit/ddcd0acf26ddd682cb0dc15a2bd6aa3b96bb1e69
- https://github.com/NaturalIntelligence/fast-xml-parser/releases/tag/v5.3.5
- https://github.com/NaturalIntelligence/fast-xml-parser/security/advisories/GHSA-m7jm-9gc2-mpf2
Products affected by CVE-2026-25896
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cpe:2.3:a:naturalintelligence:fast-xml-parser:4.1.3
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cpe:2.3:a:naturalintelligence:fast-xml-parser:4.1.4
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cpe:2.3:a:naturalintelligence:fast-xml-parser:4.2.0
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cpe:2.3:a:naturalintelligence:fast-xml-parser:4.2.1
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cpe:2.3:a:naturalintelligence:fast-xml-parser:4.2.2
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cpe:2.3:a:naturalintelligence:fast-xml-parser:4.2.3
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cpe:2.3:a:naturalintelligence:fast-xml-parser:4.2.4
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cpe:2.3:a:naturalintelligence:fast-xml-parser:4.2.5
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cpe:2.3:a:naturalintelligence:fast-xml-parser:4.2.6
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cpe:2.3:a:naturalintelligence:fast-xml-parser:4.2.7
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cpe:2.3:a:naturalintelligence:fast-xml-parser:4.3.0
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cpe:2.3:a:naturalintelligence:fast-xml-parser:4.3.1
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cpe:2.3:a:naturalintelligence:fast-xml-parser:4.3.2
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cpe:2.3:a:naturalintelligence:fast-xml-parser:4.3.3
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cpe:2.3:a:naturalintelligence:fast-xml-parser:4.3.4
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cpe:2.3:a:naturalintelligence:fast-xml-parser:4.3.5
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cpe:2.3:a:naturalintelligence:fast-xml-parser:4.3.6
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cpe:2.3:a:naturalintelligence:fast-xml-parser:4.4.0
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cpe:2.3:a:naturalintelligence:fast-xml-parser:4.4.1
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cpe:2.3:a:naturalintelligence:fast-xml-parser:4.5.0
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cpe:2.3:a:naturalintelligence:fast-xml-parser:4.5.1
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cpe:2.3:a:naturalintelligence:fast-xml-parser:4.5.2
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cpe:2.3:a:naturalintelligence:fast-xml-parser:4.5.3
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cpe:2.3:a:naturalintelligence:fast-xml-parser:5.0.0
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cpe:2.3:a:naturalintelligence:fast-xml-parser:5.0.1
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cpe:2.3:a:naturalintelligence:fast-xml-parser:5.0.2
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cpe:2.3:a:naturalintelligence:fast-xml-parser:5.0.3
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cpe:2.3:a:naturalintelligence:fast-xml-parser:5.0.4
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cpe:2.3:a:naturalintelligence:fast-xml-parser:5.0.5
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cpe:2.3:a:naturalintelligence:fast-xml-parser:5.0.6
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cpe:2.3:a:naturalintelligence:fast-xml-parser:5.0.7
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cpe:2.3:a:naturalintelligence:fast-xml-parser:5.0.8
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cpe:2.3:a:naturalintelligence:fast-xml-parser:5.0.9
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cpe:2.3:a:naturalintelligence:fast-xml-parser:5.1.0
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cpe:2.3:a:naturalintelligence:fast-xml-parser:5.2.0
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cpe:2.3:a:naturalintelligence:fast-xml-parser:5.2.1
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cpe:2.3:a:naturalintelligence:fast-xml-parser:5.2.2
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cpe:2.3:a:naturalintelligence:fast-xml-parser:5.2.3
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cpe:2.3:a:naturalintelligence:fast-xml-parser:5.2.4
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cpe:2.3:a:naturalintelligence:fast-xml-parser:5.2.5
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cpe:2.3:a:naturalintelligence:fast-xml-parser:5.3.0
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cpe:2.3:a:naturalintelligence:fast-xml-parser:5.3.1
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cpe:2.3:a:naturalintelligence:fast-xml-parser:5.3.2
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cpe:2.3:a:naturalintelligence:fast-xml-parser:5.3.3
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cpe:2.3:a:naturalintelligence:fast-xml-parser:5.3.4