A maliciously crafted QPY file can potential execute arbitrary-code embedded in the payload without privilege escalation when deserialising QPY formats < 13. A python process calling Qiskit 0.18.0 through 1.4.1's `qiskit.qpy.load()` function could potentially execute any arbitrary Python code embedded in the correct place in the binary file as part of specially constructed payload.
Qiskit SDK 0.45.0 through 1.2.4 could allow a remote attacker to cause a denial of service using a maliciously crafted QPY file containing a malformed symengine serialization stream which can cause a segfault within the symengine library.