CVE-2026-44664
MEDIUM6.1EPSS 0.01%fast-xml-builder Comment Value regex can be bypassed
Published: 5/8/2026Modified: 5/14/2026
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.
Affected packages (1)
- npm/fast-xml-builder>= 1.1.5, < 1.1.6
CVSS scores
| Source | Version | Severity | Vector |
|---|---|---|---|
| osv | CVSS 3.1 | MEDIUM6.1 | CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N |
References (4)
- ADVISORYhttps://nvd.nist.gov/vuln/detail/CVE-2026-44664
- PATCHhttps://github.com/NaturalIntelligence/fast-xml-builder
- WEBhttps://github.com/NaturalIntelligence/fast-xml-builder/security/advisories/GHSA-45c6-75p6-83cc
- WEBhttps://github.com/NaturalIntelligence/fast-xml-parser/security/advisories/GHSA-gh4j-gqv2-49f6