CVE-2026-87864 – Enabling `CURLOPT_CRLF` causes curl to advertise the raw input byte count in the `IMAP APP

Enabling `CURLOPT_CRLF` causes curl to advertise the raw input byte count in
the `IMAP APPEND {N}` literal while transmitting line-ending expanded data.
The server reads only $N$ bytes for the payload, causing the remaining
overflow bytes to be interpreted and executed as pipelined IMAP commands
within the authenticated session.