Answer in brief
CVE-2026-83617 records a High severity (CVSS 8.7) vulnerability in xmldom: requireWellFormed element/attribute name validation is bypassable via an embedded line terminator. The current sources do not mark it as known exploited. The current feed maps xmldom/xmldom (generic), @xmldom/xmldom (generic), @xmldom/xmldom (npm), @xmldom/xmldom (npm). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
CVSS is 8.7. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps xmldom/xmldom (generic), @xmldom/xmldom (generic), @xmldom/xmldom (npm), @xmldom/xmldom (npm). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| xmldom/xmldomgeneric | >= 0.9.11, < 0.9.12 | Not reported |
| @xmldom/xmldomgeneric | >= 0.9.11, < 0.9.12 | Not reported |
| @xmldom/xmldomnpm | >=0.9.11 <0.9.12 | 0.9.12 |
| @xmldom/xmldomnpm | =0.9.11 | 0.9.12 |
Published upstream
Sep 1, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Sep 8, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Sep 1, 2026
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.
Quoted source text, attributed separately from HOL analysis.