Input validation error in fast-xml-parser - CVE-2026-27942
Published: April 20, 2026
Vulnerability identifier: #VU126614
CSH Severity: Low
CVSS v4.0: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:U/U:Clear
CVE-ID: CVE-2026-27942
CWE-ID: CWE-20
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vendor: Natural Intelligence
Affected software:
fast-xml-parser
fast-xml-parser
Detailed vulnerability description
The vulnerability allows a remote user to cause a denial of service.
The vulnerability exists due to improper input validation in arrToStr in XMLBuilder when processing input with preserveOrder enabled. A remote user can supply specially crafted input to cause a denial of service.
Only applications using the XML builder with preserveOrder set to true are vulnerable.
How to mitigate CVE-2026-27942
Install security update from vendor's website.