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
Southern areas windy and very mild.
Nobel-prize-winning schoolgirl Malala Yousafzai has said she is a proud Brummie, as a new portrait of her was unveiled in her adopted home.
The Filipino girl group lost out to Lauren Murray in the sing off after receiving the lowest number of votes.