Monday August 20, 2018


Issues logging in with an upstream two factor authentication service

Technical Summary:
On Monday August 20th between 08:15AM (PT) and 09:59 AM (PT) we noticed that our users were experiencing issues using Duo Mobile to authenticate their Slack accounts. Duo Mobile was able to resolve the issue and all Slack users should be able to sign into their accounts once again. If you’re still having trouble signing in with two-factor authentication, please reach out to us at

2:00 PM PDT - Aug 20th・See in your timezone

There is good news to share: it seems the upstream issue with two factor authentication has been fixed by the affected service, so everyone should be able to log in successfully once again.

10:01 AM PDT - Aug 20th・See in your timezone

We are aware of an upstream issue with a two factor authentification service. Some folks may be unable to log in to Slack as a result. We are keeping a close eye on the issue.

8:15 AM PDT - Aug 20th・See in your timezone

Services affected