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.

The following products are affected by CVE-2026-25896 vulnerability.

Here, you will find a curated list of external links that provide in-depth information to CVE-2026-25896.

URL	Resource
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
https://nvd.nist.gov/vuln/detail/CVE-2026-25896
https://www.cve.org/CVERecord?id=CVE-2026-25896