Duo Security incident
Duo Phone Call Authentication Failure for US Based Carriers
Duo Security experienced a notice incident on March 22, 2026, lasting 4h 10m. The incident has been resolved; the full update timeline is below.
Update timeline
- investigating Mar 22, 2026, 10:13 PM UTC
We are currently observing a recurrence of the issue causing VOIP authentication failures in all deployments in the US region. We are working to correct the issue as soon as possible. While we work to resolve this, please use alternative authentication methods such as Duo Mobile Push, SMS passcodes etc. A full list of available authentication methods can be found here: https://duo.com/docs/policy#authentication-methods
- monitoring Mar 23, 2026, 12:01 AM UTC
We are now observing high rates of success of VoIP authentication. The issue appears to be resolved but we will continue to monitor the situation.
- resolved Mar 23, 2026, 02:23 AM UTC
VoIP authentication has returned to normal operation with sustained success rates observed.