GHSA-45C6-75P6-83CC

Vulnerability from github – Published: 2026-05-08 16:27 – Updated: 2026-05-14 20:37
VLAI
Summary
fast-xml-builder Comment Value regex can be bypassed
Details

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.

Severity
6.1 (Medium)
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
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{
  "affected": [
    {
      "package": {
        "ecosystem": "npm",
        "name": "fast-xml-builder"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "1.1.5"
            },
            {
              "fixed": "1.1.6"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "1.1.5"
      ]
    }
  ],
  "aliases": [
    "CVE-2026-44664"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-91"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-05-08T16:27:28Z",
    "nvd_published_at": "2026-05-13T16:16:58Z",
    "severity": "MODERATE"
  },
  "details": "# Summary\nThe fix for https://github.com/advisories/GHSA-gh4j-gqv2-49f6 in fast-xml-parser sanitizes `--` sequences in XML comment content using .replace(/--/g, \u0027- -\u0027). This skip the values containing three consecutive dashes (e.g., ---\u003e...), allowing an attacker to break out of an XML comment and inject arbitrary XML/HTML content.\n\n### Impact\nAny application with comment property enabled allow attacker to inject malicious or unwanted code like JS script tag in the XML/HTML output.\n\n### Workarounds\nCheck for the presence of 3 consecutive dashes externally in the property value used for comment tag.",
  "id": "GHSA-45c6-75p6-83cc",
  "modified": "2026-05-14T20:37:30Z",
  "published": "2026-05-08T16:27:28Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/NaturalIntelligence/fast-xml-builder/security/advisories/GHSA-45c6-75p6-83cc"
    },
    {
      "type": "WEB",
      "url": "https://github.com/NaturalIntelligence/fast-xml-parser/security/advisories/GHSA-gh4j-gqv2-49f6"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-44664"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/NaturalIntelligence/fast-xml-builder"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N",
      "type": "CVSS_V3"
    }
  ],
  "summary": "fast-xml-builder Comment Value regex can be bypassed"
}



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