GHSA-whj4-6x5x-4v2j
FITS GZIP decompression bomb in Pillow
At a glance
- Published
- Updated
- CVE
- CVE-2026-40192
- Aliases
- BIT-pillow-2026-40192, PYSEC-2026-2250
- CVSS_V3
- CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- CVSS_V4
- CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
Description
### Impact Pillow did not limit the amount of GZIP-compressed data read when decoding a FITS image, making it vulnerable to decompression bomb attacks. A specially crafted FITS file could cause unbounded memory consumption, leading to denial of service (OOM crash or severe performance degradation). ### Patches The amount of data read is now limited to the necessary amount. Fixed in Pillow 12.2.0 (PR #9521). ### Workarounds Avoid Pillow >= 10.3.0, < 12.2.0 Only open [specific image formats](https://pillow.readthedocs.io/en/stable/releasenotes/8.0.0.html#image-open-add-formats-parameter), excluding FITS.
Affected packages
| Package | Versions |
|---|---|
| PyPI · pillow | introduced 10.3.0, fixed 12.2.0 |
References
- https://github.com/python-pillow/Pillow/security/advisories/GHSA-whj4-6x5x-4v2j WEB
- https://nvd.nist.gov/vuln/detail/CVE-2026-40192 ADVISORY
- https://github.com/python-pillow/Pillow/pull/9521 WEB
- https://github.com/python-pillow/Pillow/commit/3cb854e8b2bab43f40e342e665f9340d861aa628 WEB
- https://github.com/python-pillow/Pillow PACKAGE
- https://pillow.readthedocs.io/en/stable/releasenotes/12.2.0.html#prevent-fits-decompression-bomb WEB
Sources
| Source | Licence |
|---|---|
| OSV.dev | CC-BY 4.0 — GitHub Advisory Database |