I did this

to get the the bug we need to build curl with ASAN instrumentation ...
Run this

curl -Z --url "file:/#1:8[m-p]8[1-2]mlo" --range 0-8999999999999999999

output :

... ... ... 
tool_progress.c:312:17: runtime error: signed integer overflow: 9000000000000000000 + 9000000000000000000 cannot be represented in type 'long int'

integer overflow in range value when used with parallel mode (-Z)

curl/libcurl version

curl 8.16.0 (x86_64-pc-linux-gnu) libcurl/8.16.0 OpenSSL/3.4.1 zlib/1.3.1 brotli/1.1.0 zstd/1.5.7 libidn2/2.3.8 libpsl/0.21.2 nghttp2/1.64.0 librtmp/2.3 OpenLDAP/2.6.9
Release-Date: 2025-09-10
Protocols: dict file ftp ftps gopher gophers http https imap imaps ipfs ipns ldap ldaps mqtt pop3 pop3s rtmp rtsp smb smbs smtp smtps telnet tftp ws wss
Features: alt-svc AsynchDNS brotli HSTS HTTP2 HTTPS-proxy IDN IPv6 Largefile libz NTLM PSL SSL threadsafe TLS-SRP UnixSockets zstd

operating system

Linux kali 6.11.2-amd64