Medium severity · published May 13, 2026
CVE-2026-44664
fast-xml-builder: Comment Value bypass regex
6.1
CVSS
0.2%
EPSS
No
On KEV
Description
fast-xml-builder builds XML from JSON. In 1.1.5, the fix for CVE-2026-41650 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. This vulnerability is fixed in 1.1.6.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
Required
Confidentiality
Low
Integrity
Low
Availability
None
Scope
Changed
Exploitation
Is it being used?
Exploit prediction (EPSS)0.2% · higher than 9% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
FA
fast-xml-builder · NaturalIntelligence
1.1.5 · source: vendor
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-44664
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-44664
github.com
https://github.com/NaturalIntelligence/fast-xml-builder/security/advisories/GHSA-45c6-75p6-83cc
More from fast-xml-builder
6.1
CVE-2026-44665
fast-xml-builder: Attribute values with unwanted quotes can bypass malicious or unwanted attributes