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.
Fix
Patch, vendor advisory and mitigation references on NVD 2
- https://hackmd.io/@haind-pwn/cfitsio-zdither0-dither-seed-oob-read Exploit, Mitigation, Vendor Advisory
- https://hackmd.io/@haind-pwn/cfitsio-zdither0-dither-seed-oob-read Exploit, Mitigation, Vendor Advisory
Every line above is quoted from NVD, CISA, Microsoft, the vendor's own advisory or DISA; nothing is generated.
Change history 5
- StatusAnalyzed → ModifiedNVD modified 2026-10-26 16:17
- Cpes+1 CPE criteria (now 1)NVD modified 2026-10-20 15:39
- StatusAwaiting Analysis → AnalyzedNVD modified 2026-10-20 15:39
- StatusReceived → Awaiting AnalysisNVD modified 2026-10-16 18:14
- First seenCVSS 6.9NVD modified 2026-10-15 19:17
Affected (CPE criteria) 1
cpe:2.3:a:nasa:cfitsio:*:*:*:*:*:*:*:*
References 6
- https://github.com/HEASARC/cfitsio Product
- https://github.com/HEASARC/cfitsio/blob/d6d27653740864a0483e74cff23c53e34e1dceee/imcompress.c#L5353-L5362 Product
- https://github.com/HEASARC/cfitsio/blob/d6d27653740864a0483e74cff23c53e34e1dceee/imcompress.c#L7495-L7516 Product
- https://hackmd.io/@haind-pwn/cfitsio-zdither0-dither-seed-oob-read Exploit, Mitigation, Vendor Advisory
- https://www.vulncheck.com/advisories/cfitsio-through-4.7.0-heap-out-of-bounds-read-via-negative-zdither0-seed Third Party Advisory
- https://hackmd.io/@haind-pwn/cfitsio-zdither0-dither-seed-oob-read Exploit, Mitigation, Vendor Advisory