CVE-2026-118248: Prototype Pollution

Description

Highcharts JS is a JavaScript charting library based on SVG. From 1.0.0 until 4.2.2, Highcharts Dashboards edit mode walks editableOptions propertyPath segments without rejecting prototype-related keys. An attacker who controls editableOptions can provide a path through __proto__ or constructor, and a user's edit writes the configured value onto Object.prototype. The property then becomes visible to JavaScript throughout the page, with consequences determined by the consuming application. This issue is fixed in 4.2.2.

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Weakness Type (CWE)

CWE-1321 CWE-1321

References

Other References

https://github.com/highcharts/highcharts/commit/05efb9849130461fe61992ea8f58d22edaad978b https://github.com/highcharts/highcharts/releases/tag/dashboards-v4.2.2 https://github.com/highcharts/highcharts/security/advisories/GHSA-wg5j-9wp8-2ggm

Frequently Asked Questions

What is CVE-2026-118248? +

Highcharts JS is a JavaScript charting library based on SVG. From 1.0.0 until 4.2.2, Highcharts Dashboards edit mode walks editableOptions propertyPath segments without rejecting prototype-related keys. An attacker who controls editableOptions can provide a path through __proto__ or constructor, and a user's edit writes the configured value onto Object.prototype. The property then becomes visible to JavaScript throughout the page, with consequences determined by the consuming application. This issue is fixed in 4.2.2.

How do I check if I'm vulnerable to CVE-2026-118248? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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