A scheme flooding vulnerability affects major desktop browsers, including Tor Browser, Safari, Chrome, and Firefox, posing a threat to anonymous browsing by using custom URL schemes as an attack vector. This exploit allows websites to identify users across different browsers and link their identities by accessing information about installed apps on a computer, creating a unique identifier even when using incognito mode or a VPN. The vulnerability can lead to third-party tracking and user profiling without consent, revealing details about a person's occupation or habits based on their installed applications. Despite efforts to report and fix this issue, the vulnerability has persisted for over five years and remains unresolved in most browsers, with varying degrees of protection and ease of exploitation. The article encourages open discussions on such vulnerabilities to expedite their resolution and emphasizes the need for a fix to maintain user privacy across web browsing sessions.