FFmpeg v.n6.1-3-g466799d4f5 allows a buffer over-read at ff_gradfun_blur_line_movdqa_sse2, as demonstrated by a call to the set_encoder_id function in /fftools/ffmpeg_enc.c component.
The product copies an input buffer to an output buffer without verifying that the size of the input buffer is less than the size of the output buffer, leading to a buffer overflow.