How severe is GHSA-mw4f-gj5x-6xr4?

No CVSS score has been assigned to GHSA-mw4f-gj5x-6xr4 yet. Review the advisory details and affected package list to assess your exposure.

Which packages are affected by GHSA-mw4f-gj5x-6xr4?

GHSA-mw4f-gj5x-6xr4 affects the following packages: highcharts (npm), highcharts (npm), highcharts (npm). Ecosystems affected: npm.

How do I fix GHSA-mw4f-gj5x-6xr4?

Update highcharts to 11.4.9 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-mw4f-gj5x-6xr4 is resolved across your whole dependency graph.

How do I detect GHSA-mw4f-gj5x-6xr4 in my npm dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for highcharts, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

How do I mitigate GHSA-mw4f-gj5x-6xr4 if there is no patch (or I can't update yet)?

Escape or sanitise the affected output on the server side rather than relying on client-side filtering, and add a Content-Security-Policy that blocks inline script execution so injected markup cannot run even if it reaches the page.

Is GHSA-mw4f-gj5x-6xr4 actively exploited in the wild?

No public exploit code has been indexed for GHSA-mw4f-gj5x-6xr4 yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

What is the EPSS score for GHSA-mw4f-gj5x-6xr4?

GHSA-mw4f-gj5x-6xr4 has an EPSS (Exploit Prediction Scoring System) score of 0.3%, placing it in the 27th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

What type of vulnerability is GHSA-mw4f-gj5x-6xr4?

GHSA-mw4f-gj5x-6xr4 is classified as Cross-site Scripting (XSS) (CWE-79). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation. This is a high-impact weakness class that often enables remote code execution or data exposure.

When was GHSA-mw4f-gj5x-6xr4 published, and has it been updated?

GHSA-mw4f-gj5x-6xr4 was published on October 28, 2026 and was last updated on October 28, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

📦 npm

Not in CISA KEV

Highcharts Core: `javascript:` URL in an `xlink:href` attribute survives text filtering and reaches exported chartsGHSA-mw4f-gj5x-6xr4

Fix: highcharts/highcharts@6cf359f

GHSA-mw4f-gj5x-6xr4 is a Cross-site Scripting (XSS) vulnerability in highcharts. A fix is available for highcharts — see the affected versions and patch details below.

Also known asCVE-2026-116796

Published

Oct 28, 2026

Updated

Oct 28, 2026

Affected

3 pkgs

Patched

3 / 3

Exploits

None indexed

Exploitation data as of Oct 29, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

EPSS Exploitation Probability

via FIRST.org ↗

0.3%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs27th percentile — riskier than 27% of all scored CVEsHighest risk

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

Real-World Exposure

3 pkgs affected

How broadly this vulnerability is actually deployed: weekly install volume shows current usage, and reverse-dependency count shows how many other packages break if it stays unpatched.

1Kother npm packages depend on this — each one inherits the vulnerability until it's patched upstream

highchartsnpm

3.5Mdownloads / week

Description

Impact

The filter applied to markup in text options checks href, src and a few similar attributes against an allowed-scheme list, but accepts xlink:href without that check, so an SVG anchor whose xlink:href is a javascript: URL passes the filter, whether or not the option is rendered with useHTML. In the live page the attribute is written without the XLink namespace, so browsers do not treat the anchor as a link there.

The attribute is preserved verbatim in the chart's serialised output: the SVG produced by the exporting module, including the default SVG download, declares the XLink namespace and contains the anchor, and so does the markup of the chart container. Any document that parses that output again, such as the downloaded SVG opened in a browser or a page that inlines exported or server-rendered chart markup, then holds a working link, and an attacker who controls the chart configuration can thereby run script in the origin of that document when a user activates the link.

Exploitation requires that untrusted data reach a text option such as the title, that the chart be exported or its markup be serialised and parsed again, and that a user activate the link.

Workarounds

Drop-in fix for all affected versions (10.3.2 - 13.1.0).

Add the below IIFE to run after Highcharts is loaded, before creating a chart.

!function(t){var e=t&&t.AST;if(e&&"function"==typeof e.filterUserAttributes&&!e.xlinkHrefPatched){var r=e.filterUserAttributes,n=Object.prototype.hasOwnProperty;e.filterUserAttributes=function(t){return t&&n.call(t,"xlink:href")&&!o(t["xlink:href"])&&delete t["xlink:href"],r.call(this,t)},e.xlinkHrefPatched=!0}function o(t){var r=e.allowedReferences||["https://","http://","mailto:","/","../","./","#"];return"string"==typeof t&&r.some(function(e){return 0===t.indexOf(e)})}}(Highcharts);

Obtaining the patched version

The patched releases are available from all the usual distribution channels. With npm, upgrade the affected package to the patched version listed above, for example npm install [email protected]. If you load Highcharts from the CDN, use the versioned URLs on code.highcharts.com, for example https://code.highcharts.com/13.1.1/highcharts.js. For more on each installation method, see the installation guide.

Affected Packages

3 total 3 fixed

Ecosystem	Package	Vulnerable range	Fix
📦npm	`highcharts`	≥ 10.3.2&&< 11.4.9	11.4.9`npm install highcharts@11.4.9`
📦npm	`highcharts`	≥ 12.0.0&&< 12.6.2	12.6.2`npm install highcharts@12.6.2`
📦npm	`highcharts`	≥ 13.0.0&&< 13.1.1	13.1.1`npm install highcharts@13.1.1`

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for highcharts, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update highcharts to 11.4.9 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-mw4f-gj5x-6xr4 is resolved across your whole dependency graph.
Workarounds
Escape or sanitise the affected output on the server side rather than relying on client-side filtering, and add a Content-Security-Policy that blocks inline script execution so injected markup cannot run even if it reaches the page.

Frequently Asked Questions

### Impact The filter applied to markup in text options checks `href`, `src` and a few similar attributes against an allowed-scheme list, but accepts `xlink:href` without that check, so an SVG anchor whose `xlink:href` is a `javascript:` URL passes the filter, whether or not the option is rendered with `useHTML`. In the live page the attribute is written without the XLink namespace, so browsers do not treat the anchor as a link there. The attribute is preserved verbatim in the chart's serialised output: the SVG produced by the exporting module, including the default SVG download, declares the

O3 Security · Impact-Aware SCA

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