---
id: "CVE-2026-118252"
kind: "vulnerability"
aliases: ["CVE-2026-118252", "GHSA-rcqf-f6h2-ccg9"]
title: "Highcharts Dashboards parses sidebar component labels as HTML"
severity: "high"
cvss: 8.4
epss: null
exploited: false
status: "open"
category: "package"
products: [{"name": "@highcharts/dashboards", "fixed": ["4.2.3"], "affected": ">= 1.0.0, <= 4.2.2", "ecosystem": "npm"}]
ecosystems: ["npm"]
tags: ["cwe-79", "frontend", "highcharts", "javascript", "package", "self-hosted"]
not_affected_if: ["edit-mode-disabled", "static-charts-only", "trusted-language-config"]
published_at: "2026-10-28T19:17:29+00:00"
first_seen_at: "2026-10-28T19:34:54+00:00"
updated_at: "2026-10-28T20:01:43+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-118252", "first_seen_at": "2026-10-28T19:34:54+00:00"}, {"source": "ghsa", "url": "https://github.com/advisories/GHSA-rcqf-f6h2-ccg9", "first_seen_at": "2026-10-28T20:01:43+00:00"}]
---

# Highcharts Dashboards parses sidebar component labels as HTML

Highcharts Dashboards from 1.0.0 through 4.2.2 parses component language strings as HTML in the edit-mode sidebar instead of inserting them as text. An attacker who controls the Dashboards language configuration can embed event-handler markup that runs in the hosting page's origin when a user opens the sidebar.

_Summary, check and fix written by a model from the sources; labelled as such._

## Affected

- npm:@highcharts/dashboards affected >= 1.0.0, <= 4.2.2 fixed 4.2.3

## How to check

- Check the installed Highcharts version with `npm ls highcharts` or the `version` field in `node_modules/highcharts/package.json`.
- Check whether the Dashboards edit mode is enabled in the app and whether untrusted users can set Dashboards language configuration.

## Fix

- Upgrade Highcharts to `4.2.3` or later.

## Timeline

- 2026-10-28T19:34:54+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-118252
- 2026-10-28T20:01:43+00:00 ghsa https://github.com/advisories/GHSA-rcqf-f6h2-ccg9

## From the sources

### Impact
The component language strings shown in the edit mode sidebar are parsed as HTML rather than inserted as text. An attacker who controls those language options can supply markup carrying event handlers, which execute in the origin of the page hosting the dashboard once the sidebar renders the affected labels. Exploitation requires that untrusted data reach the Dashboards language configuration and that a user open the edit mode sidebar.

### Workarounds

Until you can upgrade, patch `EditMode` once at application startup. The hook runs before the sidebar is built, so the labels are already harmless by the time they are rendered. Assigning a string to `textContent` and reading back `innerHTML` turns any markup into literal text, which is exactly what the fixed version renders.

After importing the module, use this code snipped once, before any board is created.

```js
{
    const EditMode = window.Dashboards?.EditMode;
    const escapeHTML = (text) => text
        .replace(/&/g, '&amp;')
        .replace(/</g, '&lt;')
        .replace(/>/g, '&gt;');
    const patched = new WeakSet();
    const originalInit = EditMode.prototype.init;

    EditMode.prototype.init = function (...args) {
        const labels = this.lang?.sidebar;

        if (labels && !patched.has(this)) {
            patched.add(this);

            for (const key of Object.keys(labels)) {
                if (typeof labels[key] === 'string') {
                    labels[key] = escapeHTML(labels[key]);
                }
            }
        }

        return originalInit.apply(this, args);
    };
}
```

If your application does not need Edit Mode, leaving it disabled (`editMode.enabled: false`) removes the exposure as well.

### Obtaining the patched version
The patched releases are available from all the usual distribution channels. With npm, upgrade the affected package to the patched version listed above, for example `npm install @highcharts/dashboards@4.2.3`. If you load Highcharts Dashboards from a CDN, use a versioned URL, for example `https://code.highcharts.com/dashboards/4.2.3/dashboards.js`. For more on each installation method, see the [installation guide](https://www.highcharts.com/docs/dashboards/installation).

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