Vulnerability · Published Oct 15, 2026 · Assigned by VulnCheck
CVE-2026-111125CFITSIO through 4.7.0 Heap Out-of-Bounds Read via HCOMPRESS input_nnybble
Medium 6.1
In plain English
A medium-severity out-of-bounds read in cfitsio from HEASARC. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 16% of all known vulnerabilities).
Official description
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 input_nnybble in fits_hdecompress.c. Attackers can supply a crafted FITS file with ZCMPTYPE HCOMPRESS_1 declaring oversized tile geometry to crash applications calling fits_read_pix or disclose limited heap memory.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian:12 | cfitsio | no fix listed | DEBIAN-CVE-2026-111125 |
| Debian:13 | cfitsio | no fix listed | DEBIAN-CVE-2026-111125 |
| Debian:14 | cfitsio | no fix listed | DEBIAN-CVE-2026-111125 |
| Ubuntu:22.04:LTS | cfitsio | no fix listed | UBUNTU-CVE-2026-111125 |
| Ubuntu:24.04:LTS | cfitsio | no fix listed | UBUNTU-CVE-2026-111125 |
| Ubuntu:26.04:LTS | cfitsio | no fix listed | UBUNTU-CVE-2026-111125 |
| Ubuntu:26.10 | cfitsio | no fix listed | UBUNTU-CVE-2026-111125 |
Affected products (as reported)
Weakness: CWE-125 · Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:H
References
- https://hackmd.io/@haind-pwn/cfitsio-zdither0-dither-seed-oob-read technical-description, exploit
- https://github.com/HEASARC/cfitsio/blob/d6d27653740864a0483e74cff23c53e34e1dceee/fits_hdecompress.c#L2575-L2633 technical-description
- https://github.com/HEASARC/cfitsio/blob/d6d27653740864a0483e74cff23c53e34e1dceee/imcompress.c#L6310-L6316 technical-description
- https://github.com/HEASARC/cfitsio product
- VulnCheck Advisory: CFITSIO through 4.7.0 Heap Out-of-Bounds Read via HCOMPRESS input_nnybble third-party-advisory