Outage in Quad9

OCSP Validation Broken

Resolved Major
July 03, 2025 - Started 3 months ago - Lasted about 2 hours
Official incident page

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Outage Details

After updating our SSL certificate globally, DoH/DoT implementations which rely on OCSP validation stopped working. We are already in the process of deploying a fix ASAP. We apologize for the inconvenience. Issue Start: 14:30 UTC, July 3rd
Latest Updates ( sorted recent to last )
RESOLVED 3 months ago - at 07/03/2025 08:16PM

This is resolved.

95% of our infrastructure was fixed within 60 minutes of the Issue Start time, but it took some extra time to resolve the last few PoPs.

If you're still experiencing this issue, please open a support ticket to support@quad9.net and include the output of the command below:

# macOS or Linux: run the following command in Terminal:
dig +short @9.9.9.9 cname id.server.on.quad9.net.

# Windows:  run the following command in the Command Prompt:
nslookup -q=cname id.server.on.quad9.net. 9.9.9.9

Issue Start: 14:30 UTC, July 3rd
Issue Start: 17:45 UTC, July 3rd

IDENTIFIED 3 months ago - at 07/03/2025 06:13PM

After updating our SSL certificate globally, DoH/DoT implementations which rely on OCSP validation stopped working.

We are already in the process of deploying a fix ASAP.

We apologize for the inconvenience.

Issue Start: 14:30 UTC, July 3rd

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