CVE-2026-25128

HIGH

7.5

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. 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., `&#9999999;` or `&#xFFFFFF;`). This causes the parser to throw an uncaught exception, crashing any application that processes untrusted XML input. Version 5.3.4 fixes the issue.

CVE Details

CVSS v3.1 Score7.5

SeverityHIGH

CVSS VectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Attack VectorNETWORK

ComplexityLOW

Privileges RequiredNONE

User InteractionNONE

Published1/30/2026

Last Modified2/27/2026

Sourcenvd

Honeypot Sightings0

Affected Products

naturalintelligence:fast-xml-parser

Weaknesses (CWE)

CWE-20CWE-248

References

https://github.com/NaturalIntelligence/fast-xml-parser/commit/4e387f61c4a5cef792f6a2f42467013290bf95dc(security-advisories@github.com)

https://github.com/NaturalIntelligence/fast-xml-parser/releases/tag/v5.3.4(security-advisories@github.com)

https://github.com/NaturalIntelligence/fast-xml-parser/security/advisories/GHSA-37qj-frw5-hhjh(security-advisories@github.com)

IOC Correlations

No correlations recorded

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