Slack resets passwords exposed in 2015 breach

Slack has reset passwords for close to 1% of overall Slack accounts in response to new information learned from a 2015 security breach.

The announcement affects certain accounts created prior to March 2015 and passwords not reset since then. Also, it does not affect those same accounts that use a single-sign-on (SSO) provider.

Slack also assured users this does not affect 99% of users who have joined Slack since March of 2015.

In 2015, hackers gained access to Slack infrastructure, including a database that stored sensitive customer information. Data stolen included usernames and hashed passwords.