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CVE-2026-25896

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

This page contains facts from public vulnerability sources. Check the original advisory before updating.

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.

CVSS 9.3 · Critical · EPSS 0.5% · Fix available

Published
Updated

Stack: system · node

Affected products and versions

  • fast-xml-parser

    Versions
    • >= 5.0.0, < 5.3.5: Affected
    • >= 4.1.3, < 4.5.4: Affected

    No fix published

  • node-webfont Debian:12

    Versions
    • 11.4.0+dfsg2+~cs35.7.26-10
    • 11.4.0+dfsg2+~cs35.7.26-11
    • 11.4.0+dfsg2+~cs35.7.26-12
    • 11.4.0+dfsg2+~cs35.7.26-13
    • 11.4.0+dfsg2+~cs35.7.26-14
    • 11.4.0+dfsg2+~cs35.7.26-15
    • 11.4.0+dfsg2+~cs35.7.26-16
    • 11.4.0+dfsg2+~cs35.7.26-18
    • 11.4.0+dfsg2+~cs35.7.26-19
    • 11.4.0+dfsg2+~cs35.7.26-20
    • 11.4.0+dfsg2+~cs35.7.26-21
    • 11.4.0+dfsg2+~cs35.7.26-7
    • 11.4.0+dfsg2+~cs35.7.26-8
    • 11.4.0+dfsg2+~cs35.7.26-9
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • node-webfont Debian:13

    Versions
    • 11.4.0+dfsg2+~cs35.7.26-13
    • 11.4.0+dfsg2+~cs35.7.26-14
    • 11.4.0+dfsg2+~cs35.7.26-15
    • 11.4.0+dfsg2+~cs35.7.26-16
    • 11.4.0+dfsg2+~cs35.7.26-18
    • 11.4.0+dfsg2+~cs35.7.26-19
    • 11.4.0+dfsg2+~cs35.7.26-20
    • 11.4.0+dfsg2+~cs35.7.26-21
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • node-webfont Debian:14

    Versions
    • 11.4.0+dfsg2+~cs35.7.26-13
    • 11.4.0+dfsg2+~cs35.7.26-14
    • 11.4.0+dfsg2+~cs35.7.26-15
    • 11.4.0+dfsg2+~cs35.7.26-16
    • 11.4.0+dfsg2+~cs35.7.26-18
    • 11.4.0+dfsg2+~cs35.7.26-19
    • 11.4.0+dfsg2+~cs35.7.26-20
    • 11.4.0+dfsg2+~cs35.7.26-21
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • fast-xml-parser npm

    Affected ranges
    • SEMVER: ≥ 5.0.0, < 5.3.5

    Update to 5.3.5

  • fast-xml-parser npm

    Affected ranges
    • SEMVER: ≥ 4.1.3, < 4.5.4

    Update to 4.5.4

  • node-webfont Ubuntu:24.04:LTS

    Versions
    • 11.4.0+dfsg2+~cs35.7.26-7ubuntu1
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • node-webfont Ubuntu:25.10

    Versions
    • 11.4.0+dfsg2+~cs35.7.26-10
    • 11.4.0+dfsg2+~cs35.7.26-13ubuntu2
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • node-webfont Ubuntu:26.10

    Versions
    • 11.4.0+dfsg2+~cs35.7.26-18
    • 11.4.0+dfsg2+~cs35.7.26-19
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • node-webfont Ubuntu:26.04:LTS

    Versions
    • 11.4.0+dfsg2+~cs35.7.26-13ubuntu2
    • 11.4.0+dfsg2+~cs35.7.26-14
    • 11.4.0+dfsg2+~cs35.7.26-15
    • 11.4.0+dfsg2+~cs35.7.26-16build1
    • 11.4.0+dfsg2+~cs35.7.26-18
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

Original sources

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