Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
This affects the package phpoffice/phpspreadsheet prior to 1.16.0. The library is vulnerable to XSS when creating an html output from an excel file by adding a comment on any cell. The root cause of this issue is within the HTML writer where user comments are concatenated as part of a link and this is returned as HTML.
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.