Improper input validation in Naturalintelligence Fast-Xml-Parser

CVE-2026-25128

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. In versions 5.0.9 through 5.3.3, a RangeError vulnerability exists in the numeric entity processing of fast-xml-parser when parsing XML with out-of-range entity code points (e.g., `�` or `�`). This causes the parser to throw an uncaught exception, crashing any application that processes untrusted XML input. Version 5.3.4 fixes the issue.

Vulnerability class: Drupalgeddon 2 (CVE-2018-7600)

Published · last modified .

CVSS v3 metric

CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.

EPSS exploit prediction

EPSS: 0.006 (48.7th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 49th percentile — 48.7% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2026-25128: held from 0.006 to 0.006.

EPSS over last 30 days · oldest: 0.006 · newest: 0.006 · change: +0.000

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-25128?
CVE-2026-25128 is a high-severity vulnerability in Naturalintelligence Fast-Xml-Parser, classified under Improper Input Validation. CVSS score: 7.5/10. Published 2026-01-30.
How severe is CVE-2026-25128?
High severity. CVSS v3 base score is 7.5 out of 10.