{"id":"CVE-2026-25896","summary":"fast-xml-parser has an entity encoding bypass via regex injection in DOCTYPE entity names","details":"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.","aliases":["GHSA-m7jm-9gc2-mpf2"],"modified":"2026-09-12T03:30:46.748281290Z","published":"2026-02-20T20:57:48.074Z","database_specific":{"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/25xxx/CVE-2026-25896.json","cna_assigner":"GitHub_M","cwe_ids":["CWE-185"]},"references":[{"type":"WEB","url":"https://github.com/NaturalIntelligence/fast-xml-parser/releases/tag/v5.3.5"},{"type":"WEB","url":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-25896.json"},{"type":"ADVISORY","url":"https://access.redhat.com/errata/RHSA-2026:40984"},{"type":"ADVISORY","url":"https://access.redhat.com/errata/RHSA-2026:41941"},{"type":"ADVISORY","url":"https://access.redhat.com/errata/RHSA-2026:41944"},{"type":"ADVISORY","url":"https://access.redhat.com/errata/RHSA-2026:51349"},{"type":"ADVISORY","url":"https://access.redhat.com/errata/RHSA-2026:6174"},{"type":"ADVISORY","url":"https://access.redhat.com/errata/RHSA-2026:6802"},{"type":"ADVISORY","url":"https://access.redhat.com/errata/RHSA-2026:7110"},{"type":"ADVISORY","url":"https://access.redhat.com/errata/RHSA-2026:7128"},{"type":"ADVISORY","url":"https://access.redhat.com/security/cve/CVE-2026-25896"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/25xxx/CVE-2026-25896.json"},{"type":"ADVISORY","url":"https://github.com/NaturalIntelligence/fast-xml-parser/security/advisories/GHSA-m7jm-9gc2-mpf2"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-25896"},{"type":"REPORT","url":"https://bugzilla.redhat.com/show_bug.cgi?id=2441501"},{"type":"FIX","url":"https://github.com/NaturalIntelligence/fast-xml-parser/commit/943ef0eb1b2d3284e72dd74f44a042ee9f07026e"},{"type":"FIX","url":"https://github.com/NaturalIntelligence/fast-xml-parser/commit/ddcd0acf26ddd682cb0dc15a2bd6aa3b96bb1e69"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/naturalintelligence/fast-xml-parser","events":[{"introduced":"292fb784334043214e29fa60adbb5630a36f5768"},{"fixed":"fe9a85270122036ae22637167ce38a5f71b73a5f"},{"fixed":"943ef0eb1b2d3284e72dd74f44a042ee9f07026e"},{"fixed":"ddcd0acf26ddd682cb0dc15a2bd6aa3b96bb1e69"}],"database_specific":{"cpe":"cpe:2.3:a:naturalintelligence:fast-xml-parser:*:*:*:*:*:*:*:*","extracted_events":[{"introduced":"4.1.3"},{"fixed":"5.3.5"}],"source":["CPE_RANGE","REFERENCES"]}}],"versions":["v4.5.2","v5.3.4","v5.3.3","v5.3.2","v5.3.1","v5.3.0","v5.2.5","v5.2.3","v5.2.2","v5.2.1","v5.2.0","v5.1.0","v5.0.9","v5.0.7","v5.0.6","v5.0.4","v5.0.2","v5.0.0","v4.5.1","v4.5.0","v4.4.1","v4.4.0","v4.3.6","v4.3.5","v4.3.4","v4.3.3","v4.3.2","v4.3.1","v4.3.0","v4.2.7","v4.2.6","v4.2.5","v4.2.4","v4.2.3","v4.2.0","v4.1.4","v4.1.3"],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-25896.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:H/A:N"}]}