CVE-2026-118246

Highcharts Core: breadcrumbs.style keys become SVG event-handler attributes

// Workaround fix for all affected Highcharts versions: 10.0.0-13.0.2
((H)=>{const S=H.SVGElement.prototype,D=S._defaultSetter;S._defaultSetter=function _defaultSetter(v,k,e){/^on/i.test(k)||D.call(this,v,k,e)};})(Highcharts);
// End of the workaround fix

The breadcrumbs style option is applied to the breadcrumb button as SVG attributes rather than as CSS, and the attribute names are not filtered. An attacker who controls the chart configuration can supply keys under breadcrumbs.style that name event handlers, and those keys become live handlers on the breadcrumb button, so the attacker's script runs in the origin of the page hosting the chart. The option is reached through drilldown.breadcrumbs, navigation.breadcrumbs and the breadcrumbs option of the treemap, sunburst and treegraph series. Exploitation requires that untrusted data reach the chart configuration and that a user drill down, or traverse into a level of a hierarchical series, so that the breadcrumbs render, and then hover over or activate the breadcrumb button. Charts rendered in styled mode do not apply the option and are not affected. Charts built with Highcharts Stock, Maps and Gantt are included, since those ship from the same package as Core.

Untrusted input is rendered as active markup in a victim's browser, which can run script in their session. Typical impact: session or credential theft, and actions taken as the user.

Kodem intelligence

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1. What is CVE-2026-118246? CVE-2026-118246 is a high-severity cross-site scripting (XSS) vulnerability in highcharts (npm), affecting versions >= 10.0.0, < 11.4.9. It is fixed in 11.4.9, 12.6.1, 13.1.0. Untrusted input is rendered as active markup in a victim's browser, which can run script in their session.
2. Which versions of highcharts are affected by CVE-2026-118246? highcharts (npm) versions >= 10.0.0, < 11.4.9 is affected.
3. Is there a fix for CVE-2026-118246? Yes. CVE-2026-118246 is fixed in 11.4.9, 12.6.1, 13.1.0. Upgrade to this version or later.
4. Is CVE-2026-118246 exploitable, and should I be worried? Whether CVE-2026-118246 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
5. What actually determines whether CVE-2026-118246 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
6. How do I fix CVE-2026-118246?
   • Upgrade highcharts to 11.4.9 or later
   • Upgrade highcharts to 12.6.1 or later
   • Upgrade highcharts to 13.1.0 or later

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