CVE-2026-27942CWE-120

fast-xml-parser has stack overflow in XMLBuilder with preserveOrder

Low · published February 26, 2026

CVSS v4.0
2.7
EPSS
1%
Percentile
51.4
In the wild
Unconfirmed
What it is

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.

The record
Technical detail
CVSS v4.0
2.7 · LOW
Vector
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:U
EPSS
0.00670 · 51.4th percentile
Weakness
CWE-120 · Buffer Copy without Checking Size of Input ('Classic Buffer Overflow')
Published
2026-02-26T01:22Z
EPSS history
Timeline
  • 26 FEB 01:22Z
    fast-xml-parser has stack overflow in XMLBuilder with preserveOrder
    cvelistv5