CVE-2026-25896

EUVD-2026-7529
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.
Cross-site Scripting
ProviderTypeBase ScoreAtk. VectorAtk. ComplexityPriv. RequiredVector
NISTPrimary
9.3 CRITICAL
NETWORK
LOW
NONE
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:H/A:N
Base Score
CVSS 3.x
EPSS Score
Percentile: 35%
Affected Products (NVD)
VendorProductVersion
naturalintelligencefast-xml-parser
4.1.3 ≤
𝑥
< 5.3.5
𝑥
= Vulnerable software versions
Debian logo
Debian Releases
Debian Product
Codename
node-webfont
bookworm
undetermined
forky
undetermined
sid
undetermined
trixie
undetermined