Duo Security Outage History

On Aug 26, 2025 6:30 AM UTC Duo Security began tracking an outage tied to T-Mobile US SMS delivery that caused warnings across the SMS Message Delivery components. US numbers attempting SMS-based verifications or alerts could experience delays or failures as the SMS path was affected. The issue appeared concentrated in the SMS delivery layer, with many SMS components listed as impacted while other Duo services remained reachable.

By 8:10 AM UTC, admin functions used to manage users and AD Sync on certain deployments were reported as affected, signaling a broader outage beyond SMS. At 9:10 AM UTC, Duo indicated a fix had been deployed for the User Management and SSO issues affecting Duo3, Duo47, and Duo57, and ongoing monitoring followed.

Recovery began to show by 10:25 AM UTC as many SMS delivery components came back up, with admin/SSO remaining degraded on some deployments. All services were restored by 11:45 AM UTC. Across the incident, the status page issued five updates detailing the progression from SMS delivery warnings to targeted admin panel and SSO fixes and the eventual recovery.

Duo Security experienced a region-specific outage in India that affected phone call delivery, causing failures in voice-based authentication across multiple deployments. Dozens of Duo Phone Call Delivery components were impacted (with an SMS delivery component also involved), leading to degraded or failed call-based verification for users in the region.

The incident began at Aug 18, 2025 11:25 AM UTC and was resolved by Aug 18, 2025 3:30 PM UTC, lasting about 4 hours and 5 minutes. Duo Security issued two official status updates during the event, first noting an investigation into India-specific phone call authentication failures and later confirming that services had returned to normal. The impact appears localized to India deployments with no broader global impact indicated.

Duo Security reported an issue impacting SMS-based authentication in the United States, causing delays and failures in delivering one-time codes via SMS. Dozens of SMS delivery components across multiple paths were affected, which could prevent users from receiving verification codes for login and 2FA. The outage began on 4:40 AM UTC and was resolved by 8:10 AM UTC, lasting about 3 hours and 30 minutes.

Duo’s status page showed an active investigation and advised customers to use alternate authentication methods such as Duo Push, Duo Mobile Passcodes, and hardware tokens while the carrier issues were addressed. The incident involved multiple SMS delivery components (for example DUO31, DUO46, DUO9, and many others) and saw 2 status updates before the service returned to normal.

An outage affecting the Duo Admin Panel on the DUO41 deployment caused login failures for administrators. This resulted in a brief partial outage with admins unable to sign in during the incident window. The provider moved the DUO41 Admin Panel to a degraded state and issued two status updates as they deployed a fix and monitored results. The incident lasted approximately 25 minutes, starting at Aug 6, 2025 12:05 AM UTC and ending by Aug 6, 2025 12:30 AM UTC, after which the Admin Panel returned to normal. There was no indication of broader impact beyond the DUO41 Admin Panel.

Duo Security faced an outage affecting the AI Assistant service across US deployments. Affected AI Assistant components were listed as down, with the incident beginning on 12:20 AM UTC and being resolved by 1:40 AM UTC, lasting about 1 hour 20 minutes. Users relying on AI Assistant may have experienced failures or degraded performance during this window. The incident involved dozens of AI Assistant components across US deployments, and the provider posted two status updates during the outage.

Duo Security reported an India-focused VoIP issue that prevented phone call delivery from reaching users, blocking phone-based authentication across deployments in India. The disruption degraded the ability to complete voice-based verification and impacted multiple deployments in the region.

The incident began at 12:05 PM UTC and was resolved by 9:50 PM UTC, lasting approximately 9 hours and 45 minutes. Duo Security issued 2 status updates during the incident: an initial investigation into India-specific phone call delivery failures, followed by confirmation that the affected phone call delivery paths had been restored and services returned to normal.

Duo Security experienced a brief India-focused outage affecting VoIP authentication for Phone Call Delivery. This caused degraded VoIP call delivery across multiple components and impacted users in India. The outage lasted about 5 minutes, beginning at Jul 30, 2025 11:20 AM UTC and was resolved by Jul 30, 2025 11:25 AM UTC. The incident was followed by the provider's update noting the issue appeared resolved and that monitoring would continue. The geographic impact was localized to India, with limited user feedback during the event.

Duo’s Phone Call Delivery experienced an outage affecting phone-based authentication across all deployments. The incident began on Jul 30, 2025 9:30 AM UTC and was resolved by Jul 30, 2025 11:15 AM UTC, with the service returning to normal after the issue with multiple Phone Call Delivery components was addressed. The status page documented two updates during the incident, detailing the investigation and subsequent recovery. A user in Hyderabad, India reported issues during the event, indicating that some users experienced authentication problems while the incident was active.

Duo Security reported an India-focused outage causing phone call authentication failures for VoIP calls across multiple deployments. Users in India experienced issues with phone-based authentication due to failures across numerous DUO Phone Call Delivery components. The incident began at Jul 28, 2025 12:00 PM UTC and was resolved by Jul 28, 2025 1:55 PM UTC, lasting about 1 hour and 55 minutes.

The provider posted two status updates documenting the investigation and the recovery. The impact was regionally confined to India with no broader global impact reported.

An incident in Great Britain disrupted phone-based MFA for Duo Security users as UK telephony providers experienced VoIP failures. The issue began at Jul 24, 2025 1:45 PM UTC with an investigation into the problem; a follow-up update at Jul 24, 2025 1:55 PM UTC noted GB VoIP Failures across deployments and listed dozens of Phone Call Delivery components (including DUO4, DUO7, DUO35, DUO20, and many others) as affected. Users reported difficulties completing authentication via phone calls during this period.

The incident lasted approximately 11 hours, with the service returning to normal by Jul 25, 2025 12:50 AM UTC. The provider issued 3 updates during the event, attributing the disruption to UK telephony provider issues affecting VoIP call delivery across multiple Duo deployments. Once the VoIP path was restored, phone-based authentication resumed for Duo users across Great Britain.