in June 2021 Twitter introduced an unintended vulnerability within its Application Programming Interface (API) which inadvertently enabled attackers to correlate users’ email addresses and phone numbers directly with their Twitter accounts. Although initially unnoticed this security flaw persisted within the system’s infrastructure ultimately providing a window of opportunity for exploitation. By approximately December 2021 threat actors actively discovered and exploited this vulnerability at scale. Leveraging automated scripts and targeted attack methodologies attackers systematically queried the vulnerable API endpoint effectively mapping personal contact information—specifically email addresses and phone numbers—to corresponding Twitter user profiles. This attack method significantly compromised user privacy by enabling potential identification and targeted harassment phishing attempts and social engineering campaigns. The consequence of this vulnerability was the widespread exposure of millions of Twitter user accounts encompassing a diverse range of individuals including public figures journalists activists and ordinary users globally. The exposed data potentially included usernames linked emails and registered phone numbers significantly elevating the risk of identity theft unauthorized account access and various targeted cyberattacks. Upon discovery of the breach Twitter acted swiftly to remediate the vulnerability by updating the affected API endpoints enhancing monitoring practices and implementing additional security controls aimed at preventing future exploitation. The platform subsequently notified impacted users, providing guidance to enhance account security through recommended practices such as enabling two-factor authentication and remaining vigilant against suspicious communications.