cve/2023/CVE-2023-26487.md

### [CVE-2023-26487](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2023-26487)
![](https://img.shields.io/static/v1?label=Product&message=vega&color=blue)
![](https://img.shields.io/static/v1?label=Version&message=%3D%20%3C%205.23.0%20&color=brighgreen)
![](https://img.shields.io/static/v1?label=Vulnerability&message=CWE-79%3A%20Improper%20Neutralization%20of%20Input%20During%20Web%20Page%20Generation%20('Cross-site%20Scripting')&color=brighgreen)

### Description

Vega is a visualization grammar, a declarative format for creating, saving, and sharing interactive visualization designs.`lassoAppend' function accepts 3 arguments and internally invokes `push` function on the 1st argument specifying array consisting of 2nd and 3rd arguments as `push` call argument. The type of the 1st argument is supposed to be an array, but it's not enforced. This makes it possible to specify any object with a `push` function as the 1st argument, `push` function can be set to any function that can be access via `event.view` (no all such functions can be exploited due to invalid context or signature, but some can, e.g. `console.log`). The issue is that`lassoAppend` doesn't enforce proper types of its arguments. This issue opens various XSS vectors, but exact impact and severity depends on the environment (e.g. Core JS `setImmediate` polyfill basically allows `eval`-like functionality). This issue was patched in 5.23.0.

### POC

#### Reference
- https://github.com/vega/vega/security/advisories/GHSA-w5m3-xh75-mp55

#### Github
No PoCs found on GitHub currently.