Highcharts: series column construction writes to Object.prototype

### Impact When series columns are built from point objects, the point option keys are used directly as data column ids, so the write that populates a column reaches `Object.prototype` and the `Object` constructor. Keys named `__proto__` and `constructor` survive `JSON.parse` as own enumerable properties, so an attacker who controls the point objects can set integer-keyed properties on `Object.prototype`, one per point index, to values of their choosing. Named properties cannot be reached this way. The integer keys still affect every object in the page: reading an out-of-range index on any array or plain object returns the attacker's value, and `for...in` over any object yields the injected keys, so unrelated code can take branches it should not using attacker-supplied data, and rendering can fail as a side effect. The properties remain in place once the chart has been built, and no user interaction is required beyond rendering the chart. Consequences beyond disruption depend on the consuming application. ### Workarounds Drop-in fix - for any versions affected (6.1.0-13.0.2). Add the below IIFE to run after Highcharts is loaded. ```javascript ;!function(t){if(t&&t.Point&&!t.Point.prototype.protoPollutionPatched){var o=t.Point.prototype,r=o.optionsToObject,e=o.setNestedProperty,n=Object.prototype.hasOwnProperty;o.optionsToObject=function(t){if(t&&"object"==typeof t&&!Array.isArray(t)&&(n.call(t,"__proto__")||n.call(t,"constructor"))){var o={};for(var e in t)n.call(t,e)&&!c(e)&&(o[e]=t[e]);t=o}return r.call(this,t)},o.setNestedProperty=function(t,o,r){return String(r).split(".").some(c)?t:e.call(this,t,o,r)},o.protoPollutionPatched=!0}function c(t){return"__proto__"===t||"constructor"===t}}(Highcharts); ``` [Live demo & testing](https://jsfiddle.net/BlackLabel/nopc6vhj/) ### 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 [email protected]`. If you load Highcharts from the CDN, use the versioned URLs on code.highcharts.com, for example `https://code.highcharts.com/13.1.0/highcharts.js`. For more on each installation method, see the [installation guide](https://www.highcharts.com/docs/getting-started/installation).

Source published

28 Oct 2026 19:56:13 UTC

Source modified

28 Oct 2026 20:15:06 UTC

Observed here

28 Oct 2026 20:55:42 UTC

Source terms

GitHub Advisory Database · CC-BY-4.0

Original source record · Cite this exact observation · Complete original publisher JSON

This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: osv · GitHub Advisory Database · CC-BY-4.0. Source text is retained; field grouping and change labels are provided by ChangeIntel.

CVSS_V4 · CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:L/VA:H/SC:L/SI:L/SA:L

Publisher rating · HIGH