Validation bypass via embedded-NUL input truncation

Improper input validation in jqlang jq 1.8.1 and earlier allows attackers to bypass JSON validation via embedded NUL bytes. jq_util_input_read_more uses strlen on the buffer returned by fgets, passes only the prefix before the first NUL to the parser, and silently excludes trailing bytes. Exploitation requires a workflow that treats jq as a validator but later forwards, stores, or acts on the original bytes, allowing downstream processing of unchecked data.