Archive · 20 Nov 2025
WhatsApp Privacy Breach: 3.5 Billion Users' Data Exposed
Some clever people found a way to look up and steal phone numbers and profile pictures of almost everyone using WhatsApp.
They could do this because WhatsApp had a mistake in how it lets you find your friends on the app.
WhatsApp says they fixed the mistake, but it's still a big worry because our phone numbers and pictures can be used to find out more about us.
Security researchers scraped phone numbers of 3.5 billion active WhatsApp users worldwide, including 750 million in India.
They also accessed profile photos and other details of 62% of Indian users and 57% globally.
WhatsApp's contact-discovery feature was exploited to harvest data at scale.
WhatsApp reportedly fixed the issue in October 2025 after being notified in April.
The exposed data could be used to create vast databases of personally identifiable information.
- Who
- Security researchers from the University of Vienna
- What
- Scraped WhatsApp user data
- When
- The issue was first reported in April 2025 and fixed in October 2025
- Where
- Globally, with a significant impact on Indian users
- Why
- To exploit WhatsApp's contact-discovery feature and harvest data at scale
Researchers' View
WhatsApp's View
Data exposure
Researchers' View
Massive user data was exposed, including phone numbers and profile photos.
WhatsApp's View
We acknowledge the issue and have fixed it. We're grateful to the researchers for their responsible partnership.
- Total users affected
- 3.5 billion
- Indian users affected
- 750 million
- Percentage of Indian users with scraped profile photos
- 62%
- Percentage of global users with scraped profile photos
- 57%
- WhatsApp's response
- Fixed the issue in October 2025
Sources
WhatsApp had a massive security flaw that put phone number of 3.5 billion users at risk: here's what happened
WhatsApp privacy risk? How researchers scraped data, profile pics from crores of Indian users
Massive WhatsApp security flaw exposed phone numbers and profile photos of billions of users worldwide: Were you affected?
Researchers scrape 3.5 bn phone numbers linked to WhatsApp accounts, can be used to create 'reverse phone-book'
