"Sharing photos or videos of children at scale across the online world can put their safety, privacy and wellbeing at risk," she said.
The researchers surveyed more than 1,000 parents in the UK, and then conducted follow-up interviews.
They found 45% of parents they spoke to actively put photos of their kids online - while one-in-six reported their child had experienced harms.
One concern is that the media being shared online could reveal details like birthdays, addresses, pet names, and so on - which later in life could increase the risk of identity fraud.
"Sharenting poses a real and present danger to our children," lead researcher Pamela Ugwudike said.
"By proudly sharing photos and information about children on social media, parents are unwittingly putting them at risk of harm, both online such as cyberbullying, and in the real world – not just now, but also years down the line."
She warned that, when pictures are shared, strangers could use that information to contact children not only online, but offline too.
