A use-after-free vulnerability in the pybddisasm Python bindings affects structure-valued members of INSTRUX objects. These members are exposed through Python objects that reference memory owned by the parent INSTRUX object. A retained reference to a member does not keep the parent allocation alive. Accessing the member after the parent INSTRUX object has been freed therefore accesses freed memory. Depending on how the member is used and whether the freed allocation has been reused, this may expose process memory or cause the Python process to crash. Exploitation requires an application to retain and subsequently access a member reference after the parent object has been freed. The pybddisasm package is no longer maintained.