Duo Security experienced a minor incident on August 26, 2025 affecting SMS Message Delivery and SMS Message Delivery and 1 more component, lasting 3h 52m. The incident has been resolved; the full update timeline is below.
Affected components
Update timeline
- investigating Aug 26, 2025, 06:29 AM UTC
We are currently investigating an issue affecting SMS delivery to phone numbers using T-Mobile Services in the US. Please feel free to check back here or subscribe to updates for the latest information regarding any changes or resolutions.
- identified Aug 26, 2025, 08:02 AM UTC
We have detected the issue affecting SMS delivery to phone numbers using T-Mobile Services in the US. Please feel free to check back here or subscribe to updates for the latest information regarding any changes or resolutions.
- monitoring Aug 26, 2025, 08:14 AM UTC
We are starting to see recovery post the fix implemented by our service provider for the issue affecting SMS delivery to phone numbers using T-Mobile Services in the US. Please feel free to check back here or subscribe to updates for the latest information regarding any changes or resolutions.
- resolved Aug 26, 2025, 10:21 AM UTC
Duo has confirmed that the issue affecting SMS delivery to phone numbers using T-Mobile services in the US has been fully resolved.