CVE-2026-27942

HIGH

fast-xml-parser <5.3.8 - DoS

Title source: llm
STIX 2.1

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. Prior to version 5.3.8, the application crashes with stack overflow when user use XML builder with `preserveOrder:true`. Version 5.3.8 fixes the issue. As a workaround, use XML builder with `preserveOrder:false` or check the input data before passing to builder.

Scores

CVSS v3 7.5
EPSS 0.0005
EPSS Percentile 16.7%
Attack Vector NETWORK
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

CISA SSVC

Vulnrichment
Exploitation none
Automatable no
Technical Impact partial

Details

CWE
CWE-120
Status published
Products (3)
fast-xml-parser_project/fast-xml-parser < 4.5.4
naturalintelligence/fast-xml-parser < 4.5.4
npm/fast-xml-parser 0 - 5.3.8npm
Published Feb 26, 2026
Tracked Since Feb 26, 2026