Outage in Let's Encrypt
High Domain Control Validation failure rate
Resolved Minor
September 11, 2026 - Started 5 days ago
- Lasted about 1 hour
Incident Report
Summary AI Generated
Let's Encrypt experienced elevated Domain Control Validation (DCV) failure rates for approximately one hour, affecting both the staging and production ACME API endpoints and potentially blocking subscribers from obtaining certificates. The root cause was identified as an issue with the DNS resolver in their secondary validation system, triggered by a recent change. The problematic change was reverted, with full restoration of service expected within 15 minutes of identification.
Let's Encrypt is investigating elevated failure rates for Domain Control Validation over the last hour, which may prevent subscribers from obtaining certificates.
Components affected
Let's Encrypt acme-v02.api.letsencrypt.org (Production) Let's Encrypt acme-staging-v02.api.letsencrypt.org (Staging)Trusted by 1,000+ teams
The Status Page Aggregator with Early Outage Detection
Stop finding out about outages from your users. Monitor 6,320+ cloud services and get alerted the second something breaks.
Latest Updates ( sorted recent to last )
5 days ago - at 09/11/2026 01:40AM
Let's Encrypt is investigating elevated failure rates for Domain Control Validation over the last hour, which may prevent subscribers from obtaining certificates.
5 days ago - at 09/11/2026 02:11AM
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.
Latest Let's Encrypt outages
API Degraded Performance - 3 months ago
API Degraded Performance - 3 months ago
Staging: Issuance stopped for incident drill - 6 months ago
Production API Disruption - 9 months ago
High API Latency - 9 months ago
The Status Page Aggregator with Early Outage Detection
With IsDown, you can monitor all your critical services' official status pages from one centralized dashboard and receive instant alerts the moment an outage is detected. Say goodbye to constantly checking multiple sites for updates and stay ahead of outages with IsDown.
Start free trialNo credit card required · Cancel anytime · 6320 services available
Integrations with
