xmldom is a pure JavaScript W3C standard-based (XML DOM Level 2 Core) `DOMParser` and `XMLSerializer` module. xmldom parses XML that is not well-formed because it contains multiple top level elements, and adds all root nodes to the `childNodes` collection of the `Document`, without reporting any error or throwing. This breaks the assumption that there is only a single root node in the tree, which led to issuance of CVE-2022-39299 as it is a potential issue for dependents. Update to @xmldom/xmldom@~0.7.7, @xmldom/xmldom@~0.8.4 (dist-tag latest) or @xmldom/xmldom@>=0.9.0-beta.4 (dist-tag next). As a workaround, please one of the following approaches depending on your use case: instead of searching for elements in the whole DOM, only search in the `documentElement`or reject a document with a document that has more then 1 `childNode`.

A prototype pollution vulnerability exists in the function copy in dom.js in the xmldom (published as @xmldom/xmldom) package before 0.8.3 for Node.js via the p variable. NOTE: the vendor states "we are in the process of marking this report as invalid"; however, some third parties takes the position that "A prototype injection/Prototype pollution is not just when global objects are polluted with recursive merge or deep cloning but also when a target object is polluted."