Outage in Duo Security

US SMS delivery delays and failures

Resolved Major

August 06, 2025 - Started 9 months ago - Lasted about 3 hours
Official incident page

Incident Report

We are investigating an issue causing SMS delivery delays and failures in the US. We are waiting for AT&T to fix the issues on their end. During this time, please use alternate authentication methods such as Duo Push, Duo Mobile Passcodes, Hardware Tokens etc to login to your Duo-protected integrations.

Components affected

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Latest Updates ( sorted recent to last )

RESOLVED 9 months ago - at 08/06/2025 08:06AM

The issue affecting SMS delivery to US phone numbers has been resolved. Services are now fully operational.

IDENTIFIED 9 months ago - at 08/06/2025 04:49AM

We have identified an issue causing SMS delivery delays and failures in the US. We are waiting for AT&T to fix the issues on their end.
During this time, please use alternate authentication methods such as Duo Push, Duo Mobile Passcodes, Hardware Tokens etc to login to your Duo-protected integrations.

INVESTIGATING 9 months ago - at 08/06/2025 04:40AM

We are investigating an issue causing SMS delivery delays and failures in the US. We are waiting for AT&T to fix the issues on their end.
During this time, please use alternate authentication methods such as Duo Push, Duo Mobile Passcodes, Hardware Tokens etc to login to your Duo-protected integrations.

Latest Duo Security outages

SMS Delivery Failures - 8 days ago

Duo Phone Call Authentication Failure for US Based Carriers - about 1 month ago

Service Outage on DUO81 - about 2 months ago

Service degradation on DUO81 - about 2 months ago

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