Major Security Flaw Plagues Mexico's Mandatory Telcel Biometric Registration, Exposing Millions of User Records

On January 9, 2026, Mexico’s mandatory biometric registration for mobile phone lines officially commenced, with Telcel, the nation’s largest telecommunications carrier, implementing the new system. However, a severe security vulnerability was immediately identified within Telcel’s registration portal. The flaw permitted the unauthorized exposure of sensitive personal data for registered users; merely inputting an active Telcel phone number would cause the system’s frontend to prematurely return a JSON file containing full names, RFCs (Federal Taxpayer Registry), CURPs (Unique Population Registry Key), email addresses, and even associated company names. This data exposure occurred without any prior authentication, SMS verification, or portal registration, creating a critical vector for potential identity theft, social engineering, and fraud, directly violating data protection laws and centralizing millions of user records in an unsecure flow.

Further analysis revealed the vulnerability’s simplicity: it required no advanced hacking skills, authentication tokens, or additional validation, making automated data extraction highly feasible. Compounding the issue, personal details of a developer—including their name, address, email, and birth date—were reportedly discovered embedded directly within the portal’s JavaScript code. This incident underscores a profound lack of fundamental security practices, robust quality assurance, and adequate security audits within Telcel’s development processes. The tech community’s reaction swiftly moved beyond individual developer culpability, highlighting systemic failures within a major corporation tasked with managing a government-mandated system. Experts emphasize that such critical vulnerabilities in systems handling nationwide sensitive data point to significant organizational breakdowns in software quality, secure development lifecycle, and governance, rather than isolated coding errors. Suspicions were also raised regarding coordinated efforts to downplay the severity of the flaw in public discourse, with comments appearing to dismiss the breach as inconsequential, suggesting potential bot activity or biased narratives.