CalPERS saw the personal information of 769,000 of its retired members exposed in a third-party breach earlier this month, KCRA reported this week. The fund serves more than 2 million members in its retirement system and 1.5 million in its health system, the report says. 

The California State Teachers' Retirement System, the second largest pension fund in the U.S., also suffered from the breach. It has more than 947,000 members. 

This week CalPERS said that its third party vendor, PBI Research Services, had notified it of a "vulnerability" with software used to identify member deaths and make sure payments are distributed correctly. It told CalPERS the issued had since been fixed. 

The app contains identifying information, including full names, birth dates and social security numbers. This information was accessed by an "unauthorized third party" the report says, also noting that names of family members may have also been exposed.