{"id":"CVE-2026-83618","summary":"xmldom: requireWellFormed DocType publicId/systemId validation is bypassable via an embedded line terminator","details":"xmldom is a pure JavaScript W3C standard-based (XML DOM Level 2 Core) DOMParser and XMLSerializer module. From 0.9.10 until 0.9.12, the requireWellFormed: true serializer validates DocumentType.publicId and DocumentType.systemId with PubidLiteral_match and SystemLiteral_match expressions produced by reg() in lib/grammar.js, which inherit the multiline flag. A complete valid literal on the first line can therefore satisfy the matcher while U+000A, U+000D, U+2028, or U+2029 and breakout markup remain in the emitted \u003c!DOCTYPE ...\u003e declaration. This bypasses the strict-serialization mitigation for the earlier DocumentType injection advisory; creation and direct property assignment remain unvalidated by design. This issue is fixed in @xmldom/xmldom version 0.9.12.","aliases":["GHSA-vr34-hp96-76pp"],"modified":"2026-09-04T11:30:35.344043647Z","published":"2026-09-01T14:49:46.201Z","database_specific":{"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/83xxx/CVE-2026-83618.json","cna_assigner":"GitHub_M","cwe_ids":["CWE-625","CWE-91"]},"references":[{"type":"WEB","url":"https://github.com/xmldom/xmldom/releases/tag/0.9.12"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/83xxx/CVE-2026-83618.json"},{"type":"ADVISORY","url":"https://github.com/xmldom/xmldom/security/advisories/GHSA-vr34-hp96-76pp"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-83618"},{"type":"FIX","url":"https://github.com/xmldom/xmldom/commit/7b2ec67e1750daadd0bb06c92e875e726544a362"},{"type":"FIX","url":"https://github.com/xmldom/xmldom/pull/1071"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/xmldom/xmldom","events":[{"introduced":"bf396a575c4dd32ce4bd925b849dcb7e778d957c"},{"fixed":"7b2ec67e1750daadd0bb06c92e875e726544a362"},{"fixed":"0af8cf829d8a92bbac612903422c6947f5458f06"}],"database_specific":{"extracted_events":[{"introduced":"0.9.10"},{"fixed":"0.9.12"}],"source":["AFFECTED_FIELD","REFERENCES"]}}],"versions":["0.9.11","0.9.10"],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-83618.json"}}],"schema_version":"1.9.0","severity":[{"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"}]}