RUSTSEC-2026-0396: Seekable reads a NULL or out-of-bounds seek table #39

Seekable reads a NULL or out-of-bounds seek table

Seekable did not record whether it was initialized. On a fresh Seekable,
or one whose init_buff() failed, decompress, offset_to_frame_index and
frame_decompressed_size made the C library read a NULL seek table. After a
failed re-initialization, decompress returned data from the refused buffer
using the previous seek table.

Separately, frame_decompressed_size(num_frames()), on Seekable and
SeekTable, read one entry past the end of the seek table.

The flaw was corrected by refusing to use a Seekable until an
initialization succeeded, and by checking the frame index.

See advisory page for additional details.