Using a Let’s Encrypt TLS Certificate May Throw Security Warnings
On Wednesday, March 4, 2020, 3 million Transport Layer Security (TLS) certificates issued by Let’s Encrypt will be revoked because of a Certificate Authority Authorization (CAA) bug. This is 2.6% of the over 116 million active certificates issued by Let’s Encrypt.
Let’s Encrypt has contacted all certificate holders affected by this bug, and they’ve created a tool and a list of serial numbers to determine if your TLS certificate is affected by the bug.
Let’s Encrypt have not set an exact time for revocation of the certificates, however, they say that the earliest timeframe will be UTC 00:00.
Some certificate holders have received emails that they’re affected, but they may have received that alert erroneously, either because the certificate was issued in the last few days after the bug was fixed, or by not meeting certain timing criteria necessary for the bug to trigger, adding to confusion.