Stack Overflow Vulnerability in Fast XML Parser by Natural Intelligence
CVE-2026-27942

2.7LOW

Key Information:

Vendor

Naturalintelligence

Status
Fast-xml-parser
Vendor
CVE Published:
26 February 2026

What is CVE-2026-27942?

The fast-xml-parser tool enables users to validate XML, parse XML to JavaScript objects, or construct XML from JavaScript objects without relying on C/C++ libraries or callbacks. However, versions prior to 5.3.8 are susceptible to a stack overflow crash when the XML builder is used with the option preserveOrder:true. This can lead to application instability and unexpected behavior. Users are encouraged to upgrade to version 5.3.8 or implement a workaround by setting preserveOrder:false or validating input data before it is passed to the builder.

Affected Version(s)

fast-xml-parser < 5.3.8

References

https://github.com/NaturalIntelligence/fast-xml-parser/se...
x_refsource_CONFIRM
https://github.com/NaturalIntelligence/fast-xml-parser/pu...
x_refsource_MISC
https://github.com/NaturalIntelligence/fast-xml-parser/co...
x_refsource_MISC

CVSS V4

Score:
2.7
Severity:
LOW
Confidentiality:
None
Integrity:
None
Availability:
Low
Attack Vector:
Network
Attack Complexity:
Low
Attack Required:
None
Privileges Required:
Undefined
User Interaction:
None

Timeline

  • Vulnerability published

  • Vulnerability Reserved

.