xmldom is a pure JavaScript W3C standard-based (XML DOM Level 2 Core) DOMParser and XMLSerializer module. In @xmldom/xmldom prior to versions 0.9.10 and 0.8.13 and xmldom version 0.6.0 and prior, the package allows attacker-controlled comment content to be serialized into XML without validating or neutralizing comment-breaking sequences. As a result, an attacker can terminate the comment early and inject arbitrary XML nodes into the serialized output. This issue has been patched in versions @xmldom/xmldom versions 0.9.10 and 0.8.13.