Mozilla Research Reveals Stardust Period Tracker App Shared Users' Health Data with Analytics Firm

Mozilla research found that the period tracker app Stardust shared users’ health data with an analytics firm, highlighting disparities in privacy practices among such apps. Another unnamed period tracker app tested by Mozilla was described as "squeaky clean" in contrast. The report did not specify the analytics firm involved, the exact type of health data shared, or the number of affected users. No technical details, dates, or CVE IDs were provided in the findings. The impact centers on potential privacy violations for Stardust users due to unauthorized data sharing. The research was published by TechCrunch on July 16, 2026.