HubSpot, a major player in marketing and sales software, is investigating a cybersecurity incident involving unauthorized access attempts on a limited number of customer accounts.

Alyssa Robinson, HubSpot’s chief information security officer, confirmed to TechCrunch that the company has initiated incident response procedures since June 22, contacting affected customers and taking steps to revoke unauthorized access and protect data.

The extent of the breach and the number of affected customers are still unclear. HubSpot, which has a market cap of nearly $30 billion and over 216,000 corporate clients including Discord, Eventbrite, and Talkspace, has not disclosed whether it has received any communication from the malicious actors.