Upcoming Let’s Encrypt CT Log Changes - Shutting down 2025 shards

[Matthew McPherrin]

The Let’s Encrypt 2025 CT Log shards have passed the end of their temporal windows, and are Rejected in Chrome’s log list. We will be shutting down Oak’s 2025 shards.

Sycamore and Willow, our static-ct logs, will have their 2025 shards become read-only next week. We will keep them online until at least the end of February. As part of routine maintenance and refreshing base OS images, Sycamore and Willow will be down for several minutes during the same change window next week. We will ensure that both logs are not down at the same time.

As previously announced, Oak 2026 shards are currently read-only and will remain available until the end of February, after which point they will also be shut down.

Thanks,
Matthew McPherrin
Let’s Encrypt