xmldom: requireWellFormed element/attribute name validation is bypassable via an embedded line terminator

{
  "id": "2803a5e6b2d9a9d9c1c5c621c463207596469a4e6bf90cd48d80ee709e17f96a",
  "url": "https://osv.dev/vulnerability/CVE-2026-83617",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "xmldom: requireWellFormed element/attribute name validation is bypassable via an embedded line terminator",
    "summary": "xmldom is a pure JavaScript W3C standard-based (XML DOM Level 2 Core) DOMParser and XMLSerializer module. From 0.9.11 until 0.9.12, the requireWellFormed: true element and attribute name checks use the anchored QName_exact expression produced by reg() in lib/grammar.js, which inherits the multiline flag. A name with a valid first line followed by U+000A, U+000D, U+2028, or U+2029 and breakout markup therefore passes validation and is emitted verbatim in element start and end tags or attribute names. This bypasses the strict-serialization checks introduced for the earlier element-name and attribute-name injection advisories, while the default serialization path remains outside the strict guarantee. This issue is fixed in @xmldom/xmldom version 0.9.12.",
    "evidence": "osv:CVE-2026-83617",
    "products": [],
    "severity": "high",
    "structured": {
      "id": "CVE-2026-83617",
      "aliases": [
        "CVE-2026-83617",
        "GHSA-jxjr-3g7g-3944"
      ],
      "metrics": [
        {
          "type": "CVSS_V4",
          "score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://github.com/xmldom/xmldom",
              "type": "GIT",
              "events": [
                {
                  "introduced": "1f0610959ab7b82cc7ad702d1be0243efc5791c0"
                },
                {
                  "fixed": "0af8cf829d8a92bbac612903422c6947f5458f06"
                },
                {
                  "fixed": "7b2ec67e1750daadd0bb06c92e875e726544a362"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "range": [
                      {
                        "introduced": "0.9.11"
                      },
                      {
                        "fixed": "0.9.12"
                      }
                    ],
                    "source": "AFFECTED_FIELD",
                    "strategy": "StringRangeExpression"
                  },
                  {
                    "range": [
                      {
                        "fixed": "7b2ec67e1750daadd0bb06c92e875e726544a362"
                      }
                    ],
                    "source": "REFERENCES_COMMIT"
                  },
                  {
                    "range": [
                      {
                        "fixed": "0af8cf829d8a92bbac612903422c6947f5458f06"
                      }
                    ],
                    "source": "REFERENCES_TAG",
                    "original_tag": "0.9.12"
                  }
                ]
              }
            }
          ],
          "versions": [
            "0.9.11"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-83617.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:29.967366259Z",
      "provider": "osv",
      "references": [
        "https://github.com/xmldom/xmldom/releases/tag/0.9.12",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/83xxx/CVE-2026-83617.json",
        "https://github.com/xmldom/xmldom/security/advisories/GHSA-jxjr-3g7g-3944",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-83617",
        "https://github.com/xmldom/xmldom/commit/7b2ec67e1750daadd0bb06c92e875e726544a362",
        "https://github.com/xmldom/xmldom/pull/1071"
      ],
      "provider_metadata": {
        "cwe_ids": [
          "CWE-625",
          "CWE-91"
        ],
        "cna_assigner": "GitHub_M",
        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/83xxx/CVE-2026-83617.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-83617",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 496728,
  "published_at": "2026-09-01T14:47:46.526+00:00"
}