Description
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 fits_rand_value table via a zero or negative ZDITHER0 seed. Attackers can supply a crafted FITS file with a SUBTRACTIVE_DITHER_1 compressed image, read through fits_open_file() and fits_read_pix(), to cause crashes or leak heap contents in decoded pixels.
Affected products
nasa: cfitsio
References6
- hackmd.io/@haind-pwn/cfitsio-zdither0-dither-seed-oob-read ExploitMitigationVendor Advisory
- hackmd.io/@haind-pwn/cfitsio-zdither0-dither-seed-oob-read ExploitMitigationVendor Advisory
- github.com/HEASARC/cfitsio Product
- github.com/HEASARC/cfitsio/blob/d6d27653740864a0483e74cff23c53e… Product
- github.com/HEASARC/cfitsio/blob/d6d27653740864a0483e74cff23c53e… Product
- www.vulncheck.com/advisories/cfitsio-through-4.7.0-heap-out-of-… Third Party Advisory
Metrics
- CVSS 3.1
-
7.1
HIGH
Score source: NVD
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:H - CVSS 4.0
-
6.9
MEDIUM
Score source: CNA
CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:L/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X - EPSS — exploit probability
- 0% percentile: 15 · as of 10 November 2026
- CWE
- CWE-125
Could this be exploited in your environment?
A patch closes the known hole. A penetration test shows what an attacker can still reach — with proof.