DCMTK through 3.6.6 does not handle memory free properly. The object in the program is free but its address is still used in other locations. Sending specific requests to the dcmqrdb program will incur a double free. An attacker can use it to launch a DoS attack.
https://lists.debian.org/debian-lts-announce/2024/06/msg00022.html
https://github.com/DCMTK/dcmtk/commit/a9697dfeb672b0b9412c00c7d36d801e27ec85cb