Use After Free
PDFium in Google Chrome prior to 54.0.2840.59 for Windows, Mac, and Linux; 54.0.2840.85 for Android incorrectly handled object lifecycles in CFFL_FormFillter::KillFocusForAnnot, which allowed a remote attacker to potentially exploit heap corruption via crafted PDF files.
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.