CVE-2021-39227 – Fix prototype pollution in the zrender merge and clone helper methods

https://notcve.org/view.php?id=CVE-2021-39227

ZRender is a lightweight graphic library providing 2d draw for Apache ECharts. In versions prior to 5.2.1, using `merge` and `clone` helper methods in the `src/core/util.ts` module results in prototype pollution. It affects the popular data visualization library Apache ECharts, which uses and exports these two methods directly. The GitHub Security Advisory page for this vulnerability contains a proof of concept. This issue is patched in ZRender version 5.2.1. • https://github.com/ecomfe/zrender/pull/826 https://github.com/ecomfe/zrender/releases/tag/5.2.1 https://github.com/ecomfe/zrender/security/advisories/GHSA-fhv8-fx5f-7fxf • CWE-1321: Improperly Controlled Modification of Object Prototype Attributes ('Prototype Pollution') •