Slashdot has reported:

Let's Encrypt will cut the default validity period for its TLS certificates from 90 days to 64 days on Feb. 10, 2027. Certificates issued or renewed from that date will have the shorter lifespan unless users choose one of the existing shorter options, 45 days or six days.

Certificates already issued will remain valid until their expiry dates, and the organization said it will not revoke any valid certificates during the transition. It expects the final 90-day certificate to expire on May 11, 2027. A 64-day certificate will be available in the staging environment starting Oct. 14, 2026, so administrators can test renewal configurations before the production change.

The change is part of an effort to improve web security by limiting the time compromised or incorrectly issued certificates can be used. Slashdot’s source, Linuxiac, advised administrators with cron jobs or scripts that use fixed renewal intervals to review their settings.

Let's Encrypt also plans to reduce the default certificate lifetime again, to 45 days in 2028, making the 64-day period an interim step. Separately, it will shorten the reuse period for a previously completed domain authorization from 30 days to 10 days. In 2028, that period is scheduled to fall further, to seven hours.