Integer Overflow or Wraparound
libsixel 1.8.4 has an integer overflow in sixel_frame_resize in frame.c.
CWE-190 - Integer Overflow or Wraparound
The software performs a calculation that can produce an integer overflow or wraparound, when the logic assumes that the resulting value will always be larger than the original value. This can introduce other weaknesses when the calculation is used for resource management or execution control.