On January 14, 2026, global telnet traffic observed by GreyNoise sensors fell off a cliff. A 59% sustained reduction, eighteen ASNs going completely silent, five countries vanishing from our data entirely. Six days later, CVE-2026-24061 dropped. Coincidence is one explanation.
The pattern points toward one or more North American Tier 1 transit providers implementing port 23 filtering
I remember using telnet on a Palm Pilot, linked to the internet via IRDA to my (pre-smart) cell phone to log into my companies’ server to fix something while I was on holidays.