Highcharts Dashboards / Grid Pro: DataTable.setCell and column writers treat __proto__ as an existing column.

Exploitation

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

CVSS 4.0

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

EPSS

• CVE-2026-118247: 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 When a single cell value is written to a data table, the column id is used as a key on the table's column collection without filtering, so a column id of `proto` resolves to `Object.prototype`, is taken for an existing column, and the write lands at the row index on `Object.prototype`; a column id of `constructor` writes onto the `Object` constructor in the same way. In Dashboards releases that still supported column aliases, the id is first resolved through the alias map, so a literal `proto` id is redirected harmlessly there, while an alias whose target is `proto`, which the connector's data table options accept, reaches the same write. An attacker who controls the column id can thereby set integer-keyed properties on `Object.prototype`, one per row index, holding the written value; named properties cannot be reached through these paths, because the row index is a number. The integer keys still affect every object in the page: reading an out-of-range index on…

Published by the source

28 Oct 2026, 19:55 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-c75x-9x9h-28rm

2. Revision 1 · created · 28 Oct 2026

   Published from ghsa record GHSA-c75x-9x9h-28rm

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# Patch Next advisory brief: CVE-2026-118247

Advisory: Highcharts Dashboards / Grid Pro: `DataTable.setCell` and column writers treat `__proto__` as an existing column.
IDs: CVE-2026-118247, GHSA-c75x-9x9h-28rm
Record: https://patchnext.com/advisories/cve-2026-118247 (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: Medium (CVSS 6.9)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: @highcharts/grid-pro 3.2.0; @highcharts/dashboards 4.2.2. A vendor fix does not mean a deployment is fixed.

## Affected components
- npm @highcharts/grid-pro: affected >= 2.0.0, < 3.2.0; fixed in 3.2.0
- npm @highcharts/dashboards: affected >= 1.0.0, < 4.2.2; fixed in 4.2.2

## Suggested inspection (read-only)
- `npm ls @highcharts/grid-pro --all`: lists every installed copy and version, including transitive ones. Run in the project root after `npm ci`.
- `npm ls @highcharts/dashboards --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/grid-pro, @highcharts/dashboards.
- 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-c75x-9x9h-28rm (GitHub-reviewed advisory GHSA-c75x-9x9h-28rm lists affected ranges: npm @highcharts/dashboards >=1.0.0 =2.0.0 <=3.1.0)
- Verified: https://osv.dev/vulnerability/GHSA-c75x-9x9h-28rm (OSV record GHSA-c75x-9x9h-28rm lists affected ranges: npm @highcharts/dashboards >=1.0.0 =2.0.0 <3.2.0 (fixed))

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