The leading UK site for parents has had users data compromised by hackers then using 'Heartbleed' exploit.
Mumsnet sent an email to users, warning that the hackers may have passwords and personal messages before network administrators were able to fix the vulnerability.
The website has urged all users to change their passwords.
More top news
The former Scottish Secretary was behind a controversial leaked memo released in the countdown to the general election, an inquiry has found
Warm sunny spells and some showers through rest of today across the UK, particularly in the southeast
A Norwich supporter feared he would miss out on the club's biggest match for years after a barking mad incident