GNOME libsoup before 3.6.1 allows a buffer overflow in applications that perform conversion to UTF-8 in soup_header_parse_param_list_strict. There is a plausible way to reach this remotely via soup_message_headers_get_content_type (e.g., an application may want to retrieve the content type of a request or response).
The product writes data past the end, or before the beginning, of the intended buffer.
The product copies an input buffer to an output buffer without verifying that the size of the input buffer is less than the size of the output buffer, leading to a buffer overflow.