Highcharts: dotted series.keys paths write to Object.prototype

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS 4.0

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

EPSS

• CVE-2026-118250: 0.36% estimated exploitation activity in the next 30 days; percentile 30.20 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

Impact A dot-separated key path taken from `series.keys` is followed without filtering the individual segments. An attacker who controls `series.keys` and the matching point data can use a path such as `proto.polluted` to set arbitrary properties on `Object.prototype`. The resulting properties are visible to all JavaScript running in the page, not only to the chart. No user interaction is required beyond rendering the chart. The injected properties are inert until other code on the page reads them, so consequences 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 ((H)=>{const X = H.isObject;H.Point.prototype.setNestedProperty = function setNestedProperty(t,e,i){let s=i.split(".");return s.some(t=>"proto"===t||"constructor"===t)||s.reduce(function(t,i,s,o){let r=o.length-1===s;return t[i]=r?e:X(t[i],!0)?t[i]:{},t[i]},t),t};})(Highcharts); ``` Live…

Published by the source

28 Oct 2026, 19:56 UTC

Last modified by the source

28 Oct 2026, 20:15 UTC

Source last checked

29 Oct 2026, 06:00 UTC

1. Revision 2 · amended · 29 Oct 2026

   Amended from osv record GHSA-rmqc-xvr3-v46c

2. Revision 1 · created · 28 Oct 2026

   Published from ghsa record GHSA-rmqc-xvr3-v46c

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# Patch Next advisory brief: CVE-2026-118250

Advisory: Highcharts: dotted series.keys paths write to Object.prototype
IDs: CVE-2026-118250, GHSA-rmqc-xvr3-v46c
Record: https://patchnext.com/advisories/cve-2026-118250 (revision 2, source checked 29 Oct 2026, 06:00 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: High (CVSS 7.2)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: highcharts 13.1.0, 12.6.1, 11.4.9. A vendor fix does not mean a deployment is fixed.

## Affected components
- npm highcharts: affected >= 12.0.0, < 12.6.1; >= 13.0.0, < 13.1.0; >= 6.1.0, < 11.4.9; fixed in 11.4.9, 13.1.0, 12.6.1

## Suggested inspection (read-only)
- `npm ls highcharts --all`: lists every installed copy and version, including transitive ones. Run in the project root after `npm ci`.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on highcharts.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-rmqc-xvr3-v46c (GitHub-reviewed advisory GHSA-rmqc-xvr3-v46c lists affected ranges: npm highcharts >=12.0.0 =13.0.0 =6.1.0 <11.4.9)
- Verified: https://osv.dev/vulnerability/GHSA-rmqc-xvr3-v46c (OSV record GHSA-rmqc-xvr3-v46c lists affected ranges: npm highcharts >=12.0.0 =13.0.0 =6.1.0 <11.4.9 (fixed))

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