CVE-2026-25896

Publication date 20 February 2026

Last updated 27 February 2026

Ubuntu priority

Medium

Why this priority?

Cvss 3 Severity Score

9.3 · Critical

Score breakdown

Description

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.

Read the notes from the security team

Status

Package Ubuntu Release Status
node-webfont 25.10 questing
Needs evaluation
24.04 LTS noble
Needs evaluation
22.04 LTS jammy Not in release

Notes

rodrigo-zaiden

fast-xml-parser is included in node-webfront

Severity score breakdown

Parameter Value
Base score 9.3 · Critical
Attack vector Network
Attack complexity Low
Privileges required None
User interaction None
Scope Changed
Confidentiality Low
Integrity impact High
Availability impact None
Vector CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:H/A:N

References

Other references