LG Uplus Launches SIM Card Replacement to Address IMSI Vulnerability

• •LG Uplus launched a SIM replacement program on April 15, 2026, due to IMSI vulnerabilities.
• •Over 181,000 transactions occurred on the first day, with nearly 96,000 SIM updates.
• •The initiative aims to prevent user tracking following a major hacking incident at SK Telecom.

LG Uplus has initiated a SIM card replacement program to mitigate a vulnerability in its IMSI system, which could allow third parties to track users by linking phone numbers with external data. The program began on April 15, 2026, with over 181,000 transactions processed on the first day, including nearly 96,000 SIM updates and over 85,000 physical replacements. Customers can check their eligibility for updates or replacements via the U+one app or the company website. The initiative was prompted by a significant hacking incident at SK Telecom in 2025, leading LG Uplus to randomize its IMSI scheme. The company aims to minimize customer inconvenience through a dual-response framework that includes both online and offline support. LG Uplus has deployed 5,700 personnel across 1,719 stores and is also providing services at senior welfare centers and for military personnel. The company emphasizes that this action is a proactive step to enhance security and customer confidence in mobile services.