Cross-Origin Resource Sharing (CORS) is a security feature implemented through headers set by web servers to regulate which domains can send requests to a specific server, preventing unauthorized data access and interaction. Misconfigurations in CORS can lead to significant security vulnerabilities, allowing malicious domains to bypass restrictions and access sensitive data. Common mistakes include reflecting origin headers, using insufficient regular expressions, allowing requests from localhost in production, and misconfiguring third-party hosts like Amazon S3 or domains like JSBin and CodePen. Such misconfigurations often stem from attempts to automate CORS policies or oversight during development, resulting in vulnerabilities like prefix checks where only the beginning of an origin is verified. Detectify, a continuous web scanner, offers automated scanning to identify these vulnerabilities, highlighting the importance of correctly configuring CORS to protect against unauthorized access.