Similar labels reportedly led to selecting the weak key set
The reported mismatch is that keys intended to help establish trust for website connections were allegedly weak enough to guess almost immediately. eMudhra reportedly attributed this to a certificate-generation script error: a second, weak set of keys was created and then selected because its labels resembled those of the proper keys.
The report says Mozilla, Google, and Apple added blocks or protections, while eMudhra said most affected intermediates were not used in production and it found no evidence that they issued end-user certificates. It also says there is no evidence the weak keys were abused.