Answer in brief
CVE-2026-83606 records a High severity (CVSS 8.7) vulnerability in xmldom PI grammar regex ReDoS: quadratic backtracking on unterminated processing instructions. The current sources do not mark it as known exploited. The current feed maps xmldom/xmldom (generic), @xmldom/xmldom (generic), @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). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| xmldom/xmldomgeneric | >= 0.9.0-beta.9, < 0.9.11 | Not reported |
| @xmldom/xmldomgeneric | >= 0.9.0-beta.9, < 0.9.11 | Not reported |
| @xmldom/xmldomnpm | >=0.9.0-beta.9,<=0.9.10 | 0.9.11 |
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.9 until 0.9.11, the processing-instruction production in lib/grammar.js lets the greedy S+ separator and lazy Char*? data group repeatedly repartition a long whitespace tail when the required closing ?> is absent. Both parsePI and parseProcessingInstruction apply the expression to the entire remaining source, causing quadratic backtracking during DOMParser.parseFromString() under default options and allowing a small unauthenticated XML input to stall the Node.js event loop. This issue is fixed in @xmldom/xmldom version 0.9.11.
Quoted source text, attributed separately from HOL analysis.