CVE-2026-118244

Highcharts Core: HTML text parsing falls back to unfiltered innerHTML during printing

((n)=>{n.AST.prototype.parseMarkup=function parseMarkup(t){let e,i=[];t=t.trim().replace(/ style=(["'])/g," data-style=$1");try{e=new DOMParser().parseFromString(tI?tI.createHTML(t):t,"text/html")}catch{}if(!e)try{e=new DOMParser().parseFromString(t,"text/html")}catch{}e||((e=n.doc.implementation.createHTMLDocument("")).body.innerHTML=t);let s=(t,e)=>{let i=t.localName||t.nodeName.toLowerCase(),o={tagName:i};"#text"===i&&(o.textContent=t.textContent||"");let r=t.attributes;if(r){let t={};[].forEach.call(r,e=>{"data-style"===e.name?o.style=tB.parseStyle(e.value):t[e.name]=e.value}),o.attributes=t}if(t.childNodes.length){let e=[];[].forEach.call(t.childNodes,t=>{s(t,e)}),e.length&&(o.children=e)}e.push(o)};return[].forEach.call(e.body.childNodes,t=>s(t,i)),i};})(Highcharts);

When the HTML text parser cannot obtain a document from DOMParser because the call throws, it falls back to assigning the raw markup to the innerHTML of an element created in the hosting document, and the allow-list is applied only to the resulting DOM afterwards. In Chromium the Trusted Types policy callback that the parser uses throws while a beforeprint handler is running, so if the hosting page re-renders the chart from a beforeprint handler, every HTML-rendered text option parsed at that moment, such as useHTML titles, axis labels and data labels or text set by responsive rules, is inserted unsanitized, and event handlers embedded in that markup run in the origin of the page hosting the chart. Exploitation requires that untrusted data reach the chart configuration, that the hosting page update the chart from a beforeprint handler in Chromium, and that printing be started, which the print item of the exporting menu does on its own. 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.

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1. What is CVE-2026-118244? CVE-2026-118244 is a high-severity cross-site scripting (XSS) vulnerability in highcharts (npm), affecting versions >= 12.0.0, < 12.6.1. It is fixed in 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-2026-118244? highcharts (npm) versions >= 12.0.0, < 12.6.1 is affected.
3. Is there a fix for CVE-2026-118244? Yes. CVE-2026-118244 is fixed in 12.6.1, 13.1.0. Upgrade to this version or later.
4. Is CVE-2026-118244 exploitable, and should I be worried? Whether CVE-2026-118244 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-2026-118244 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-2026-118244?
   • Upgrade highcharts to 12.6.1 or later
   • Upgrade highcharts to 13.1.0 or later

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