Let's Encrypt incident

High Domain Control Validation failure rate

Minor Resolved View vendor source →

Let's Encrypt experienced a minor incident on September 11, 2026 affecting acme-v02.api.letsencrypt.org (Production) and acme-staging-v02.api.letsencrypt.org (Staging) and 1 more component, lasting 58m. The incident has been resolved; the full update timeline is below.

Started
Sep 11, 2026, 01:40 AM UTC
Resolved
Sep 11, 2026, 02:39 AM UTC
Duration
58m
Detected by Pingoru
Sep 11, 2026, 01:40 AM UTC

Affected components

acme-v02.api.letsencrypt.org (Production)acme-staging-v02.api.letsencrypt.org (Staging)portal.letsencrypt.org (Production) (High Assurance Datacenter 2)portal-staging.letsencrypt.org (Staging) (High Assurance Datacenter 1)

Update timeline

  1. investigating Sep 11, 2026, 01:40 AM UTC

    Let's Encrypt is investigating elevated failure rates for Domain Control Validation over the last hour, which may prevent subscribers from obtaining certificates. Back to current status Status History Powered by Status.io Subscribe to receive status updates by email Close Subscribe Manage Subscription Manage Existing Subscription Create New Subscription Subscribe to receive status updates in Microsoft Teams Enter your Microsoft Teams webhook. View Instructions Email address for managing subscription Close Subscribe Manage Subscription Manage Existing Subscription Create New Subscription Subscribe to receive status updates via RSS RSS Feed Close Subscribe to receive status updates in Slack Slack channel ID Find the channel ID: Select the channel in your Slack workspace. The channel ID is displayed in the browser URL. Example: https://app.slack.com/client/T04SJBK1C/ C03SKGJ1P Email address Close Manage Subscription Manage Existing Subscription Create New Subscription Subscribe to receive status updates via iCalendar iCalendar Feed Close

  2. investigating Sep 11, 2026, 01:40 AM UTC

    Let's Encrypt is investigating elevated failure rates for Domain Control Validation over the last hour, which may prevent subscribers from obtaining certificates.

  3. identified Sep 11, 2026, 02:11 AM UTC

    We have identified an issue with our DNS resolver in our secondary validation. The change is being reverted, and we expect to be operational within 15 minutes.

  4. identified Sep 11, 2026, 02:11 AM UTC

    We have identified an issue with our DNS resolver in our secondary validation. The change is being reverted, and we expect to be operational within 15 minutes.

  5. resolved Sep 11, 2026, 02:39 AM UTC

    The incident has been resolved. Validations are succeeding.