XML entity vulnerabilities are a security risk that can be exploited by attackers through XML external entity (XXE) injection attacks, which allow them to gain access to files or infrastructure on their target server or network. XXE injections occur when an attacker takes advantage of external entity declarations in an XML document to execute malicious code. This can lead to various vulnerabilities such as data retrieval, server-side request forgery, remote code execution, and out-of-band exfiltration. To prevent these attacks, it is essential to disable support for external entities, use a web application firewall (WAF), implement zero-trust security, run automated XXE vulnerability scans, keep security patches up-to-date, reduce risks with Snyk protection capabilities, and follow best practices in error handling and input validation. By understanding the potential vulnerabilities of XML and taking proactive measures to secure it, developers can prevent these types of attacks and protect their applications from exploitation.