CVE-2026-44664 fast-xml-builder: Comment Value bypass regex
An attacker can inject arbitrary XML or HTML content by bypassing comment sanitization, potentially leading to cross-site scripting or code execution.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- A user has to click or open something
- Fix
- Available
What is CVE-2026-44664?
CVE-2026-44664 is a medium-severity cross-site scripting vulnerability in NaturalIntelligence fast-xml-builder, published on 13 May 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Official 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.
Weakness: CWE-91
Which versions are affected by CVE-2026-44664?
2 open source packages ship an affected version, including fast-xml-builder.
| Package | Affected | Fixed in |
|---|---|---|
fast-xml-builder npm | From 1.1.5 | 1.1.6 |
fast-xml-builder npm | From 1.1.5 | 1.1.6 |
How do I fix CVE-2026-44664?
Upgrade fast-xml-builder to 1.1.6 or later.
Escape output for the context it lands in and set a strict Content Security Policy. Upgrading the affected component is the real fix. More about Cross-site scripting.
Is CVE-2026-44664 being exploited?
There is no known exploitation of CVE-2026-44664 in the wild and no public exploit code.
Sources
Also known as ECHO-7046-085f-179a, GHSA-45c6-75p6-83cc, MINI-7qqw-r5m9-38gm, MINI-83f7-qrgh-ghfj, MINI-9jf8-mcg2-r99q, MINI-gmgf-4mg5-fqrq and 5 more.