GHSA-fj3w-jwp8-x2g3
fast-xml-parser has stack overflow in XMLBuilder with preserveOrder
Quick fix
GHSA-fj3w-jwp8-x2g3 — fast-xml-parser: upgrade to the fixed version with the command below.
npm install fast-xml-parser@5.3.8Details
### Impact Application crashes with stack overflow when user use XML builder with `prserveOrder:true` for following or similar input
``` [{ 'foo': [ { 'bar': [{ '@_V': 'baz' }] } ] }] ```
Cause: `arrToStr` was not validating if the input is an array or a string and treating all non-array values as text content. _What kind of vulnerability is it? Who is impacted?_
### Patches Yes in 5.3.8
### Workarounds Use XML builder with `preserveOrder:false` or check the input data before passing to builder.
### References [_Are there any links users can visit to find out more?_](https://github.com/NaturalIntelligence/fast-xml-parser/pull/791)
Are you affected?
Enter the version of the package you're using.
Affected packages
References
- https://github.com/NaturalIntelligence/fast-xml-parser/security/advisories/GHSA-fj3w-jwp8-x2g3[WEB]
- https://nvd.nist.gov/vuln/detail/CVE-2026-27942[ADVISORY]
- https://github.com/NaturalIntelligence/fast-xml-parser/pull/791[WEB]
- https://github.com/NaturalIntelligence/fast-xml-parser/commit/c13a961910f14986295dd28484eee830fa1a0e8a[WEB]
- https://github.com/NaturalIntelligence/fast-xml-parser[PACKAGE]