Transmission before 1.92 allows an attacker to cause a denial of service (crash) or possibly have other unspecified impact via a large number of tr arguments in a magnet link.
https://www.openwall.com/lists/oss-security/2010/04/01/9
https://security-tracker.debian.org/tracker/CVE-2010-0748
https://github.com/transmission/transmission/wiki/Release-Notes#transmission-192-20100314