In early 2013, Tumblr suffered a data breach that resulted in the exposure of over 65 million accounts.
The data was later put up for sale on a dark market website and included email addresses and passwords stored as salted SHA1 hashes.
Source: https://haveibeenpwned.com/PwnedWebsites#JukinMedia
TPRM report: https://scoringcyber.rankiteo.com/company/tumblr
"id": "tum114441222",
"linkid": "tumblr",
"type": "Data Leak",
"date": "02/2013",
"severity": "85",
"impact": "3",
"explanation": "Attack with significant impact with internal employee data leaks"
{'affected_entities': [{'customers_affected': '65 million',
'industry': 'Social Media',
'name': 'Tumblr',
'type': 'Company'}],
'data_breach': {'data_encryption': 'salted SHA1 hashes',
'number_of_records_exposed': '65 million',
'type_of_data_compromised': ['email addresses', 'passwords']},
'description': 'In early 2013, Tumblr suffered a data breach that resulted in '
'the exposure of over 65 million accounts. The data was later '
'put up for sale on a dark market website and included email '
'addresses and passwords stored as salted SHA1 hashes.',
'impact': {'data_compromised': ['email addresses', 'passwords']},
'initial_access_broker': {'data_sold_on_dark_web': 'Dark market website'},
'title': 'Tumblr Data Breach',
'type': 'Data Breach'}