---
id: CVE-2026-83606
title: >-
  xmldom is a pure JavaScript W3C standard-based (XML DOM Level 2 Core)
  DOMParser and XMLSerializer module
summary: >-
  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*…
severity: high
cwe:
  - CWE-400
  - CWE-1333
vendor: xmldom
product: '@xmldom/xmldom'
affected:
  - '@xmldom/xmldom >= 0.9.0-beta.9, <= 0.9.10'
patched:
  - '@xmldom/xmldom 0.9.11'
published: '2026-09-01'
updated: '2026-09-08'
sourceUpdated: '2026-09-08T21:11:31.703'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-83606'
references:
  - url: >-
      https://github.com/xmldom/xmldom/commit/73df6b8bdbd86f904b9e8c3ab9c49aa54ef2802e
    label: security-advisories@github.com
  - url: 'https://github.com/xmldom/xmldom/pull/1039'
    label: security-advisories@github.com
  - url: 'https://github.com/xmldom/xmldom/releases/tag/0.9.11'
    label: security-advisories@github.com
  - url: 'https://github.com/xmldom/xmldom/security/advisories/GHSA-g53g-w8rj-fmg7'
    label: security-advisories@github.com
  - url: 'https://github.com/xmldom/xmldom/security/advisories/GHSA-g53g-w8rj-fmg7'
    label: 134c704f-9b21-4f2e-91b3-4a467353bcc0
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-83606'
  - url: 'https://github.com/advisories/GHSA-g53g-w8rj-fmg7'
  - url: >-
      https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-83606.json
  - url: 'https://access.redhat.com/security/cve/CVE-2026-83606'
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2526808'
  - url: 'https://www.cve.org/CVERecord?id=CVE-2026-83606'
tags:
  - nvd
  - ghsa
  - npm
  - csaf
  - vex
  - red-hat
epss: 0.00524
epssPercentile: 0.41922
aliases:
  - GHSA-g53g-w8rj-fmg7
ecosystem: npm
ingestedAt: '2026-09-08T21:11:12.322Z'
cvss: 7.5
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H'
cvssSource: vendor
---

## Overview

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.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.

## Package advisory (CVE-2026-83606)

Affected packages:

- `@xmldom/xmldom >= 0.9.0-beta.9, <= 0.9.10`

Patched in:

- `@xmldom/xmldom 0.9.11`

Source: https://github.com/advisories/GHSA-g53g-w8rj-fmg7

## Vendor advisories

- **Red Hat VEX** · Important · affected: Red Hat OpenShift Container Platform 4 · no fix planned: Red Hat OpenShift Container Platform 4 · updated 2026-09-18 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-83606.json)