What’s Vulnerable › Vulnerabilities

CVE-2026-111124: CFITSIO through 4.7.0 Heap Out-of-Bounds Read via Negative ZDITHER0 Seed

• Severity: high (CVSS 7.1 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.2% probability of exploitation in the next 30 days
• Public exploit or detection template: yes
• Published: 2026-10-15 · updated 2026-10-26
• Weakness: CWE-125

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

• HEASARC cfitsio: through 4.7.0

References

• https://github.com/HEASARC/cfitsio
• https://github.com/HEASARC/cfitsio/blob/d6d27653740864a0483e74cff23c53e34e1dceee/imcompress.c#L5353-L5362
• https://github.com/HEASARC/cfitsio/blob/d6d27653740864a0483e74cff23c53e34e1dceee/imcompress.c#L7495-L7516
• https://hackmd.io/@haind-pwn/cfitsio-zdither0-dither-seed-oob-read
• https://www.vulncheck.com/advisories/cfitsio-through-4.7.0-heap-out-of-bounds-read-via-negative-zdither0-seed
• https://hackmd.io/@haind-pwn/cfitsio-zdither0-dither-seed-oob-read

Get alerted when CVE-2026-111124 or the next vulnerability affects your stack