CVE-2026-118243
Highcharts Dashboards: `__proto__` data table id writes sync listeners to `Object.prototype`
Highcharts JS is a JavaScript charting library based on SVG. From 1.0.0 until 4.2.2, Highcharts Dashboards stores DataCursor listener and state maps in plain objects keyed by DataTable ID. A __proto__ table ID supplied through dataPool connector configuration resolves to Object.prototype, and sync registration creates an enumerable property there whose suffix can be influenced through the sync group option. The property is visible on every object, and lasting sync states can throw and stop features such as extremes synchronization. Exploitation requires untrusted dashboard configuration and an enabled component sync, but no user interaction beyond loading the board. This issue is fixed in 4.2.2.
Fixes and workarounds
Fix
@highcharts/dashboards (npm): OSV reports a fixed version 4.2.2. Check the advisory for supported release branches.
Source: OSV GHSA-jqgh-w3cc-7jqwAffected products and versions
| Product | Versions | Authority |
|---|---|---|
| highcharts highcharts |
>= 1.0.0, < 4.2.2 (affected) | CNA: GitHub_M |
@highcharts/dashboards@highcharts/dashboards
npm |
≥ 1.0.0; < 4.2.2 (affected, semver); OSV events: introduced 1.0.0; fixed 4.2.2Source events (semver)Other versions: unaffected |
OSV GHSA-jqgh-w3cc-7jqw |
Version ranges are source assertions. Check the vendor advisory and your installed configuration before determining exposure.
CVSS assessments
| Version / score | Vector | Authority |
|---|---|---|
| 4.0 / 5.3 medium |
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:L/VA:L/SC:L/SI:L/SA:L | CNA: GitHub_M |
Exploit evidence
No exploit evidence in collected sources. This is not proof of no exploitation.
References
- https://github.com/highcharts/highcharts/security/advisories/GHSA-jqgh-w3cc-7jqwCNA: GitHub_M · x_refsource_CONFIRM
- https://github.com/highcharts/highcharts/commit/ade5a41a700212f09133223ca990a3737d1d9ec6CNA: GitHub_M · x_refsource_MISC
- https://github.com/highcharts/highcharts/releases/tag/dashboards-v4.2.2CNA: GitHub_M · x_refsource_MISC
- https://github.com/advisories/GHSA-jqgh-w3cc-7jqwOSV / GitHub Security Advisories · advisory
- https://osv.dev/vulnerability/GHSA-jqgh-w3cc-7jqwOSV / GitHub Security Advisories · osv
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