Duo Security incident
All Deployments: Duo Phone Call and SMS Delivery Failure
Duo Security experienced a major incident on October 20, 2025 affecting Phone Call Delivery and Phone Call Delivery and 1 more component, lasting 2h 38m. The incident has been resolved; the full update timeline is below.
Affected components
Update timeline
- investigating Oct 20, 2025, 08:29 AM UTC
We are currently investigating an issue causing phone call and SMS delivery authentication failures on all of our deployments and are working to correct the issue as soon as possible. Please check back here or subscribe to updates for any changes.
- identified Oct 20, 2025, 08:52 AM UTC
We've identified the cause of degraded Phone Authentication and SMS delivery failures. Our providers have acknowledged an upstream issue and are working on a resolution. This may affect users relying on phone calls or SMS for authentication across all deployments and we suggest using alternate means of MFA such as Duo Push if possible. Our team is working on mitigation steps and will continue to provide updates as progress is made.
- resolved Oct 20, 2025, 11:06 AM UTC
The issue affecting phone-based authentication and SMS delivery has now been resolved. System performance has remained stable, and all services are operating as expected across deployments. We will continue to monitor for any anomalies, but no further impact is anticipated at this time.