LY Corp: a LINE Album defect showed thumbnails of other users' album images, affecting over 120,000 users in Japan

1. 2024-11-28 15:35

   It began rolling out the system update that contained the cause of the defect. [1]

2. 2024-11-28 17:50

   The defect occurred as traffic grew with the rollout of the update. [1]

3. 2024-11-28 22:09

   It detected the defect internally. [1]

4. 2024-11-28 23:15

   It fixed the system so that no new defects would occur. [1]

5. 2024-11-29

   It announced the case. From 06:00 it began rolling out a fix to clear the device cache for users who kept seeing wrong thumbnails. [1] [2] [3]

6. 2024-11-30 01:14

   The fix that removes the wrong thumbnails reached all users. [1]

7. 2024-12-06

   It began notifying users in Japan who may have been affected through LINE. [1]

When processing that turns compressed album images into thumbnails peaked, image data was mixed during conversion. The original images in albums and images outside albums were not affected. Wrong thumbnails appeared in 0.3% or less of the images and accesses concerned. No logs remain, so the numbers are estimates: about 70,000 users in Japan (about 135,000 including overseas) had their thumbnails shown in others' albums, and about 55,000 in Japan (about 114,000) saw others' thumbnails. [1]