Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
The Gutenberg plugin through 13.7.3 for WordPress allows stored XSS by the Contributor role via an SVG document to the "Insert from URL" feature. NOTE: the XSS payload does not execute in the context of the WordPress instance's domain; however, analogous attempts by low-privileged users to reference SVG documents are blocked by some similar products, and this behavioral difference might have security relevance to some WordPress site administrators.
CWE-79 - Cross Site Scripting
Cross-Site Scripting, commonly referred to as XSS, is the most dominant class of vulnerabilities. It allows an attacker to inject malicious code into a pregnable web application and victimize its users. The exploitation of such a weakness can cause severe issues such as account takeover, and sensitive data exfiltration. Because of the prevalence of XSS vulnerabilities and their high rate of exploitation, it has remained in the OWASP top 10 vulnerabilities for years.