LG Uplus said it has self-reported a leak of Ixsio call data to the Personal Information Protection Commission.

The company said a cache-setting error during recent service improvement work on Ixsio caused temporary exposure of the call recipient’s phone number, call time and call summary of 36 users to 101 other users. It said it completed the report to the commission at about 9 a.m. on December 6.

The data leak occurred from 8 p.m. on December 2 to 10:59 a.m. on December 3. It was exposed to 101 users who installed or reinstalled Ixsio during that period. Each person’s data was exposed to between one and six other users.

LG Uplus said the leaked information did not include unique identifiers such as resident registration or passport numbers, and did not include financial information.

The company said it began identifying the cause and restoring the service immediately after discovering the issue at about 10 a.m. on December 3. It said it completed measures to prevent further visibility of the exposed call data and notified all affected customers by phone. It used text messages for customers who were difficult to reach.

A company official said, “We apologise for the inconvenience and concern caused to our customers,” and said the incident was not related to hacking. The official said the company would fully cooperate with the investigation by relevant authorities.