Use After Free
Acrobat Reader DC version 21.007.20099 (and earlier), 20.004.30017 (and earlier) and 17.011.30204 (and earlier) are affected by a use-after-free vulnerability in the processing of Format event actions that could result in arbitrary code execution in the context of the current user. Exploitation of this issue requires user interaction in that a victim must open a malicious file.
CWE-416 - Use After Free
Use-after-free (UaF) vulnerability occurs when the application is using a pointer to memory that has been freed. Any attempt to read/write to a buffer after it is de-allocated allows memory corruption, sensitive information exposure, and can potentially lead to arbitrary code execution.