Slack has announced its December update on its Android app introduced a bug that has been storing user's login information, passwords included, as plaintext. You'll want to change it now.
The popular messaging app sent a security update email detailing the bug introduced on December 21, causing some versions of its Android app to log user credentials as clear text, meaning passwords for many users could clearly be seen. The email went on to state that as of January 21, the issue has now been fixed, but users need to change their password.
As shown on Android Police, the email sent to users isn't a scam as Slack has confirmed the issue. Not only is it advised to change you Slack password, but to also wipe the Android app's data as logs will still store any login information used. Finally, users will also want to change the passwords of any other sites or apps if the same one has been used. Annoying? Indeed, but better safe than sorry.
First and foremost, update the latest version of Slack on Android though the Play Store. Then, in order to reset your password on Slack, head to the help center and reset your password on a PC (as passwords can't be reset on mobile devices).
As for clearing data on the Android app, on your device head to the Apps menu in Settings and select Slack, go into Storage and press Clear Data or Storage. There, you should be secure.
Slack is one of the most popular business chat apps out there, but there are plenty more messaging apps that offer a host of different features.