TikTok on Tuesday said it slammed the door on a cyberattack that targeted high-profile accounts including CNN.

The number of accounts compromised was "very small" and TikTok has beefed up defenses to thwart the method used by the hackers, according to a spokesperson.

"We have taken measures to stop this attack and prevent it from happening in the future," the spokesperson said in response to an AFP inquiry.

"We're working directly with affected account owners to restore access, if needed."

TikTok did not detail the exploit used by attackers, but media reports indicated it involved a direct messaging feature.

The attack on big brand and celebrity accounts by "malicious actors" was brought to TikTok's attention by CNN, according to the spokesperson.

"We have been collaborating closely with CNN to restore account access and implement enhanced security measures to safeguard their account moving forward," the spokesperson said.

News site Semafor was the first to report that CNN's account was compromised last week, forcing the network to suspend its TikTok presence for several days.