GitHub Advisoryadvisory · npm
GHSA-45c6-75p6-83cc fast-xml-builder Comment Value regex can be bypassed
MEDIUM
Official page ↗
- Aliases
- CVE-2026-44664
- Ecosystem
- npm
- Packages
- fast-xml-builder
- Severity
- Moderate
- CVSS vector
- CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
- Weaknesses
- CWE-91
- Reviewed
- 2026-05-08
Affected packages
• npm fast-xml-builder: >= 1.1.5, < 1.1.6 → fixed in 1.1.6
Description
Summary
The fix for https://github.com/advisories/GHSA-gh4j-gqv2-49f6 in fast-xml-parser sanitizes `--` sequences in XML comment content using .replace(/--/g, '- -'). This skip the values containing three consecutive dashes (e.g., --->...), allowing an attacker to break out of an XML comment and inject arbitrary XML/HTML content.
Impact
Any application with comment property enabled allow attacker to inject malicious or unwanted code like JS script tag in the XML/HTML output.
Workarounds
Check for the presence of 3 consecutive dashes externally in the property value used for comment tag.
Related
Alias · CVE (1)
- CVE-2026-44664 fast-xml-builder builds XML from JSON. vulnerability
Weakness · CWE (1)
- CWE-91 XML Injection weakness
References
- https://github.com/NaturalIntelligence/fast-xml-builder/security/advisories/GHSA-45c6-75p6-83cc web
- https://github.com/NaturalIntelligence/fast-xml-parser/security/advisories/GHSA-gh4j-gqv2-49f6 web
- https://nvd.nist.gov/vuln/detail/CVE-2026-44664 advisory
- https://github.com/NaturalIntelligence/fast-xml-builder package