We discussed this in the cross-signing catchup last week, and decided against using "new" everywhere because these might have been log-ins created before you opened riot. Nad will review copy, but for now, we'd use "unknown" for both log-ins created during your riot session, and log-ins created before you opened riot. In a later phase, we'd distinguish.

"Unverified login" might be enough or 'Unverified account login", given it's clear contextually that the login will be yours.

I've updated the copy in Figma to "Unknown login. Was this you?". In context it's the least ambiguous and seems to correct the right sense of urgency.