CVE-2026-44664
fast-xml-builder Comment Value regex can be bypassed
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.
How to fix CVE-2026-44664
To remediate CVE-2026-44664, upgrade the affected package to a fixed version below.
- —upgrade to 1.1.6 or later
Is CVE-2026-44664 being exploited?
Low — EPSS is 0.0%, meaning exploitation activity has not been observed at scale.
Affected packages (1)
- >= 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 |