The vulnerability allows an unauthenticated attacker on the same network to open a persistent TCP connection to port 9100 (JetDirect/RAW) and send keep‑alive packets. Because the printer firmware does not enforce connection timeouts or limits, the printer’s session threads remain locked in a waiting state, rendering the device unresponsive to all user commands and print jobs. The printer can be regained only through a manual restart, and the attack can be launched again immediately.

HP Envy 5000 series printers running firmware VERBASPP1N003.2237A.00 are affected. No other vendors or product versions are listed.

The flaw can be exercised by any device on the same local network without authentication, giving the attacker direct control over the printer’s availability. EPSS information is unavailable and the vulnerability is not listed in the CISA KEV catalog, but the lack of resource limits and timeouts suggests a high likelihood of successful exploitation. Once executed, the denial of service can be repeated repeatedly, requiring physical intervention to restore service.