Answer in brief
CVE-2026-83612 records a High severity (CVSS 8.7) vulnerability in xmldom: HTML raw-text closing-tag case mismatch causes output amplification. 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 | >= 0.9.0-beta.1, < 0.9.12 | Not reported |
| xmldom/xmldomgeneric | >= 0.9.0-beta.1, < 0.9.12 | Not reported |
| @xmldom/xmldomnpm | >=0.9.0-beta.1,<=0.9.11 | 0.9.12 |
| @xmldom/xmldomnpm | >=0.9.0-beta.1 <0.9.12 | 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 0.9.0-beta.1 until 0.9.12, HTML-mode parsing through DOMParser.parseFromString() mishandles a mixed-case closing tag for the script, style, textarea, or title raw-text elements. parseHtmlSpecialContent, selected by isHTMLRawTextElement or isHTMLEscapableRawTextElement, uses a case-sensitive indexOf() and then calls substring() with a missing-close result of negative one, causing unstable parser progression and quadratic output amplification. A small untrusted text/html document can consequently consume disproportionate CPU and memory when parsed and serialized. This issue is fixed in @xmldom/xmldom version 0.9.12.
Quoted source text, attributed separately from HOL analysis.