CVE-2026-118249: Highcharts · series column construction writes to Object.prototype
Affects highchartsSource GCVE Database
Not known to be exploited · CVSS 7.2 High : upgrade to 13.1.0 soon.
Data as of 28 Oct 2026, 21:14 UTC
- Patch
- Available – fixed in 13.1.0
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:H/VA:H/SC:L/SI:L/SA:LExploitation evidence
Disclosed: evidence found.
CVE published 28 Oct 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.
What to do
Upgrade highcharts to 13.1.0.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| npmhighcharts | Affected
| Fixed in
|
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
Description
### 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 highcharts@13.1.0`. 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).
References
- github.com/highcharts/highcharts/security/advisories/GHSA-gfvx-2c2g-38wq (opens in a new tab)
- nvd.nist.gov/vuln/detail/CVE-2026-118249 (opens in a new tab)
- github.com/highcharts/highcharts/pull/25321 (opens in a new tab)
- github.com/highcharts/highcharts/commit/d3357705c8f348904441327e32f50ab528c3a205 (opens in a new tab)
- github.com/highcharts/highcharts (opens in a new tab)
- github.com/highcharts/highcharts/releases/tag/v13.1.0 (opens in a new tab)