Medium

xmldom: Parser silently accepts a not-well-formed end tag whose name is followed by a line break and trailing content

Type: advisorySources: OSV

xmldom is a pure JavaScript W3C standard-based (XML DOM Level 2 Core) DOMParser and XMLSerializer module. Prior to @xmldom/xmldom versions 0.8.15 and 0.9.12, and in xmldom version 0.6.0 and earlier, DOMParser.parseFromString() can silently accept an end tag such as , close the element, and discard the trailing content. On 0.9.x, the lib/sax.js end-tag validator inherits the multiline flag from reg(), allowing the first line to satisfy the anchored XML ETag production; older lines have no equivalent residue validation. This parser differential can bypass a parse-before-trust well-formedness gate, although it does not inject the discarded content; onError on 0.9.x and errorHandler on 0.8.x are the relevant reporting interfaces. This issue is fixed in @xmldom/xmldom versions 0.8.15 and 0.9.12; no fixed version is available for xmldom.

Products: Not specified
Affected versions: Not specified
Fixed versions: Not specified
CVEs: CVE-2026-83611
Confirmed fixed CVEs: Not specified
Updated in this feed: 8 Nov 2026, 01:23 UTC · Revision 1

Source evidence

xmldom: Parser silently accepts a not-well-formed end tag whose name is followed by a line break and trailing content

core-osv · Original source

Published 1 Sept 2026, 14:34 UTC

osv:CVE-2026-83611

Complete source record

{
  "id": "e30747f105d8b10d4ff060223f3a3bf1d0b81131a5e14d50dee3ae4c7b2552b6",
  "url": "https://osv.dev/vulnerability/CVE-2026-83611",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "xmldom: Parser silently accepts a not-well-formed end tag whose name is followed by a line break and trailing content",
    "summary": "xmldom is a pure JavaScript W3C standard-based (XML DOM Level 2 Core) DOMParser and XMLSerializer module. Prior to @xmldom/xmldom versions 0.8.15 and 0.9.12, and in xmldom version 0.6.0 and earlier, DOMParser.parseFromString() can silently accept an end tag such as , close the element, and discard the trailing content. On 0.9.x, the lib/sax.js end-tag validator inherits the multiline flag from reg(), allowing the first line to satisfy the anchored XML ETag production; older lines have no equivalent residue validation. This parser differential can bypass a parse-before-trust well-formedness gate, although it does not inject the discarded content; onError on 0.9.x and errorHandler on 0.8.x are the relevant reporting interfaces. This issue is fixed in @xmldom/xmldom versions 0.8.15 and 0.9.12; no fixed version is available for xmldom.",
    "evidence": "osv:CVE-2026-83611",
    "products": [],
    "severity": "medium",
    "structured": {
      "id": "CVE-2026-83611",
      "aliases": [
        "CVE-2026-83611",
        "GHSA-6h8r-xr42-gp59"
      ],
      "metrics": [
        {
          "type": "CVSS_V4",
          "score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://github.com/xmldom/xmldom",
              "type": "GIT",
              "events": [
                {
                  "introduced": "0"
                },
                {
                  "last_affected": "c80a161172cc4d8733583bf0cf59abfa589f6d9e"
                },
                {
                  "introduced": "8c7c7afe89027641aa59c101d20eefedc0f54c6f"
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                {
                  "fixed": "0af8cf829d8a92bbac612903422c6947f5458f06"
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                {
                  "introduced": "c568938641cc1f121cef5b4df80fcfda1e489b6e"
                },
                {
                  "fixed": "b5b8fb5b579ae1183b34e74b3bc39d7eb50a226a"
                },
                {
                  "fixed": "4430189660b0d380ee9c9ee7550a1358688e8828"
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                {
                  "fixed": "7b2ec67e1750daadd0bb06c92e875e726544a362"
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              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "range": [
                      {
                        "introduced": "0"
                      },
                      {
                        "last_affected": "0.6.0"
                      }
                    ],
                    "source": "AFFECTED_FIELD",
                    "strategy": "StringRangeExpression"
                  },
                  {
                    "range": [
                      {
                        "introduced": "0.9.0"
                      },
                      {
                        "fixed": "0.9.12"
                      }
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                    "source": "AFFECTED_FIELD",
                    "strategy": "StringRangeExpression"
                  },
                  {
                    "range": [
                      {
                        "introduced": "0.7.0"
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                      {
                        "fixed": "0.8.15"
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                    ],
                    "source": "AFFECTED_FIELD",
                    "strategy": "StringRangeExpression"
                  },
                  {
                    "range": [
                      {
                        "fixed": "4430189660b0d380ee9c9ee7550a1358688e8828"
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                    ],
                    "source": "REFERENCES_COMMIT"
                  },
                  {
                    "range": [
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                        "fixed": "7b2ec67e1750daadd0bb06c92e875e726544a362"
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                    ],
                    "source": "REFERENCES_COMMIT"
                  },
                  {
                    "range": [
                      {
                        "fixed": "b5b8fb5b579ae1183b34e74b3bc39d7eb50a226a"
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                    ],
                    "source": "REFERENCES_TAG",
                    "original_tag": "0.8.15"
                  },
                  {
                    "range": [
                      {
                        "fixed": "0af8cf829d8a92bbac612903422c6947f5458f06"
                      }
                    ],
                    "source": "REFERENCES_TAG",
                    "original_tag": "0.9.12"
                  }
                ]
              }
            }
          ],
          "versions": [
            "0.8.14",
            "0.9.11",
            "0.8.13",
            "0.9.10",
            "0.9.9",
            "0.8.12",
            "0.8.11",
            "0.8.10",
            "0.9.8",
            "0.9.7",
            "0.9.6",
            "0.9.5",
            "0.9.4",
            "0.9.3",
            "0.9.2",
            "0.9.1",
            "0.9.0",
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            "0.8.6",
            "0.8.5",
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            "0.8.3",
            "0.8.2",
            "0.8.1",
            "0.8.0",
            "0.7.3",
            "0.7.2",
            "0.7.1",
            "0.7.0+scoped",
            "v0.7.0",
            "0.7.0+unscoped",
            "0.7.0",
            "0.6.0",
            "0.5.0",
            "0.4.0",
            "0.3.0",
            "0.2.1",
            "0.2.0",
            "v0.1.28-xmldom-alpha",
            "v0.1.28-not-published",
            "xmldom-aplha@v0.1.28",
            "v0.1.27",
            "0.1.27",
            "0.1.26",
            "0.1.25",
            "0.1.24",
            "0.1.23",
            "0.1.22",
            "0.1.21",
            "0.1.20",
            "0.1.19",
            "0.1.18",
            "0.1.17",
            "0.1.2",
            "0.1.1",
            "0.1.0"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-83611.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:52.717906779Z",
      "provider": "osv",
      "references": [
        "https://github.com/xmldom/xmldom/releases/tag/0.8.15",
        "https://github.com/xmldom/xmldom/releases/tag/0.9.12",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/83xxx/CVE-2026-83611.json",
        "https://github.com/xmldom/xmldom/security/advisories/GHSA-6h8r-xr42-gp59",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-83611",
        "https://github.com/xmldom/xmldom/commit/4430189660b0d380ee9c9ee7550a1358688e8828",
        "https://github.com/xmldom/xmldom/commit/7b2ec67e1750daadd0bb06c92e875e726544a362",
        "https://github.com/xmldom/xmldom/pull/1071",
        "https://github.com/xmldom/xmldom/pull/1072"
      ],
      "provider_metadata": {
        "cwe_ids": [
          "CWE-1286"
        ],
        "cna_assigner": "GitHub_M",
        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/83xxx/CVE-2026-83611.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-83611",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 521307,
  "published_at": "2026-09-01T14:34:12.618+00:00"
}