CVE-2026-40192

Pillow is vulnerable to a FITS GZIP decompression bomb

CVSS 8.7 HIGHEPSS 0.5%CWE-400 CWE-770

Vexday Risk Score

21Low

SSVC decision (CISA)

Track

No exploitation signal → monitor

CVSS 8.7EPSS 0.5%KEV nãoPoC —Nuclei —Metasploit —Patch —

Lifecycle

15 Apr 2026Published on NVD

Recommendation: Monitor — no exploitation signal at the moment.

Pillow is a Python imaging library. Versions 10.3.0 through 12.1.1 did not limit the amount of GZIP-compressed data read when decoding a FITS image, making them 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). If users are unable to immediately upgrade, they should only open specific image formats, excluding FITS, as a workaround.

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

Affected products

python-pillow · Pillow

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References

https://github.com/python-pillow/Pillow/commit/3cb854e8b2bab43f40e342e665f9340d861aa628 https://github.com/python-pillow/Pillow/pull/9521 https://github.com/python-pillow/Pillow/security/advisories/GHSA-whj4-6x5x-4v2j https://pillow.readthedocs.io/en/stable/releasenotes/12.2.0.html#prevent-fits-decompression-bomb