# CVE-2026-118250: Highcharts: dotted series.keys paths write to Object.prototype

Status: published. Published: 2026-10-28. Updated: 2026-11-03.

Highcharts JS is a JavaScript charting library based on SVG. From 6.1.0 until 11.4.9, 12.6.1, and 3.1.0, Highcharts follows dot-separated series.keys paths without filtering each segment. An attacker who controls series.keys and matching point data can use a path through __proto__ to assign arbitrary named properties to Object.prototype. Those properties are visible to all JavaScript in the page, and no user interaction is required beyond rendering the chart. This issue is fixed in 11.4.9, 12.6.1, and 3.1.0.

## Remediation

- fix: highcharts (npm): OSV reports a fixed version 12.6.1. Check the advisory for supported release branches. (source: OSV GHSA-rmqc-xvr3-v46c) — https://github.com/advisories/GHSA-rmqc-xvr3-v46c
- fix: highcharts (npm): OSV reports a fixed version 13.1.0. Check the advisory for supported release branches. (source: OSV GHSA-rmqc-xvr3-v46c) — https://github.com/advisories/GHSA-rmqc-xvr3-v46c
- fix: highcharts (npm): OSV reports a fixed version 11.4.9. Check the advisory for supported release branches. (source: OSV GHSA-rmqc-xvr3-v46c) — https://github.com/advisories/GHSA-rmqc-xvr3-v46c

## Affected products and versions

- highcharts / highcharts: >= 6.1.0, < 11.4.9 (affected); >= 12.0.0, < 12.6.1 (affected); >= 13.0.0, < 13.1.0 (affected). Source: CNA: GitHub_M
-  / highcharts (highcharts): ≥ 12.0.0; < 12.6.1 (affected, semver); OSV events: introduced 12.0.0; fixed 12.6.1. Source: OSV GHSA-rmqc-xvr3-v46c
-  / highcharts (highcharts): ≥ 13.0.0; < 13.1.0 (affected, semver); OSV events: introduced 13.0.0; fixed 13.1.0. Source: OSV GHSA-rmqc-xvr3-v46c
-  / highcharts (highcharts): ≥ 6.1.0; < 11.4.9 (affected, semver); OSV events: introduced 6.1.0; fixed 11.4.9. Source: OSV GHSA-rmqc-xvr3-v46c

## Severity and prioritization

- CVSS 4.0: 7.2 (high); 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; source: CNA: GitHub_M

- CISA KEV: No listing in collected sources

- EPSS: 0.36% as of 2026-11-02; percentile 30.15%

- SSVC: exploitation none; automatable no; technical impact total; source ADP: CISA-ADP

- Weaknesses: CWE-1321

## Exploit evidence

No exploit evidence in collected sources. This is not proof of no exploitation.

## References

- https://github.com/highcharts/highcharts/security/advisories/GHSA-rmqc-xvr3-v46c (CNA: GitHub_M; x_refsource_CONFIRM)

- https://github.com/highcharts/highcharts/pull/25313 (CNA: GitHub_M; x_refsource_MISC)

- https://github.com/highcharts/highcharts/commit/fd4ee8140732618bbe71295aba55398fb1f8fa9e (CNA: GitHub_M; x_refsource_MISC)

- https://github.com/highcharts/highcharts/releases/tag/v13.1.0 (CNA: GitHub_M; x_refsource_MISC)

- https://github.com/advisories/GHSA-rmqc-xvr3-v46c (OSV / GitHub Security Advisories; advisory)

- https://osv.dev/vulnerability/GHSA-rmqc-xvr3-v46c (OSV / GitHub Security Advisories; osv)

## Provenance

- CNA: GitHub_M: https://www.cve.org/CVERecord?id=CVE-2026-118250; retrieved 2026-11-03; source updated 2026-11-03

- OSV / GitHub Security Advisories: https://osv.dev/vulnerability/GHSA-rmqc-xvr3-v46c; retrieved 2026-11-03; source updated 2026-10-28

- FIRST EPSS: https://api.first.org/data/v1/epss?cve=CVE-2026-118250; retrieved 2026-11-03; source updated Not reported

Revision: 2efa824df4657df3b676ac2f100e9bafa923a22762927d09b465b72a514c24d0

Canonical: https://y2.dev/cve/CVE-2026-118250

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