# CVE-2026-118248: Highcharts Dashboards prototype pollution in edit mode

Source: https://junglewise.ai/threats/cve-2026-118248-highcharts-js-is-a-javascript-charting-library-based-on-svg-from  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-10-28. Updated: 2026-10-28  
License: CC BY 4.0 with a link back

CVE-2026-118248 · Severity: info · Published 2026-10-28

Highcharts Dashboards is a JavaScript library for building interactive dashboards and visualizations on web pages. When edit mode is enabled, an attacker who controls dashboard configuration can inject properties into JavaScript's Object.prototype through crafted property paths, potentially causing application malfunction or data exposure depending on how the application uses prototype-inherited properties.

Technologies: [Highcharts Dashboards](https://junglewise.ai/threats/technologies/dashboards). Vendors: [Highcharts](https://junglewise.ai/threats/vendors/highcharts).

## Quick answers

**Is CVE-2026-118248 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-118248 being exploited in the wild.

**How severe is CVE-2026-118248?** Informational severity, published 28 October 2026.

**Which products and versions are affected?** Highcharts Dashboards 1.0.0 to 4.2.1.

**Is there a fix for CVE-2026-118248?** Yes: fixed in Dashboards 4.2.2. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-118248 attacked?** It is attacked over the network, in a software library.

**Am I affected by CVE-2026-118248?** Check whether you run Highcharts Dashboards at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## How to fix

- Fixed in Dashboards 4.2.2

## Technical details

The vulnerability is a prototype pollution flaw in the edit mode's property path handler. The code processes editableOptions paths without validating against prototype-pollution attack vectors (__proto__, constructor, prototype keys). An attacker can craft a path that writes arbitrary values to Object.prototype, making those properties visible across the entire page's JavaScript scope. The fix adds explicit rejection of dangerous path segments.

## Affected products

- Highcharts Dashboards 1.0.0 to 4.2.1

## Timeline

- 2026-10-02: patched: dashboards-v4.2.2 released
- 2026-10-28: disclosed

## References

- [https://github.com/highcharts/highcharts/commit/05efb9849130461fe61992ea8f58d22edaad978b](https://github.com/highcharts/highcharts/commit/05efb9849130461fe61992ea8f58d22edaad978b)
- [https://github.com/highcharts/highcharts/releases/tag/dashboards-v4.2.2](https://github.com/highcharts/highcharts/releases/tag/dashboards-v4.2.2)

## Related threats

- [Highcharts Dashboards cross-site scripting in fullscreen label](https://junglewise.ai/threats/cve-2026-118253-highcharts-js-is-a-javascript-charting-library-based-on-svg-from)
- [Highcharts Dashboards XSS in edit-mode sidebar](https://junglewise.ai/threats/cve-2026-118252-highcharts-js-is-a-javascript-charting-library-based-on-svg-from)
- [Highcharts DataTable prototype pollution via column ID](https://junglewise.ai/threats/cve-2026-118247-highcharts-js-is-a-javascript-charting-library-based-on-svg-from)
- [Highcharts Dashboards arbitrary property injection via chartConstructor](https://junglewise.ai/threats/cve-2026-118245-highcharts-js-is-a-javascript-charting-library-based-on-svg-from)
- [Highcharts Dashboards prototype pollution via table IDs](https://junglewise.ai/threats/cve-2026-118243-highcharts-js-is-a-javascript-charting-library-based-on-svg-from)