Process crash via unterminated empty-string buffer

Heap-buffer overflow in jqlang jq 1.7.1 and earlier allows attackers to crash the process via an empty-string formatting path. jvp_string_empty_new leaves the empty string's data without a trailing null byte, so jv_string_vfmt passes an unterminated buffer to printf formatting that reads beyond its heap allocation. Exploitation requires control of a jq program that reaches empty-string indexing, and the demonstrated consequence is a jq process abort rather than data disclosure or code execution.