curl 7.7 through 7.76.1 suffers from an information disclosure when the "-t" command line option, known as "CURLOPT_TELNETOPTIONS" in libcurl, is used to send variable=content pairs to TELNET servers. Due to a flaw in the option parser for sending NEW_ENV variables, libcurl could be made to pass on uninitialized data from a stack based buffer to the server, resulting in potentially revealing sensitive internal information to the server using a clear-text network protocol.