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)
EPSS: 0.006 (44.9th percentile) — read the EPSS interpretation.
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.
Affected products
- Naturalintelligence Fast-xml-parser — versions >= 5.0.9, <= 5.3.3
Weakness classification (CWE)
References
- security-advisories@github.com (x_refsource_CONFIRM, Exploit, Vendor Advisory)
- security-advisories@github.com (Patch, x_refsource_MISC)
- security-advisories@github.com (x_refsource_MISC, Release Notes)
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.