CFITSIO through 4.7.0 contains a heap-based out-of-bounds read vulnerability in the HCOMPRESS tile decoder that allows attackers to read past the compressed tile buffer via inputnnybble in fitshdecompress.c. Attackers can supply a crafted FITS file with ZCMPTYPE HCOMPRESS1 declaring oversized tile geometry to crash applications calling fitsreadpix or disclose limited heap memory.

CFITSIO through 4.7.0 contains a heap-based out-of-bounds read vulnerability in the imcompress.c unquantize helpers that allows attackers to read memory before the fitsrandvalue table via a zero or negative ZDITHER0 seed. Attackers can supply a crafted FITS file with a SUBTRACTIVEDITHER1 compressed image, read through fitsopenfile() and fitsreadpix(), to cause crashes or leak heap contents in decoded pixels.