CVE-2026-40192
Pillow is vulnerable to a FITS GZIP decompression bomb
Description
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.
INFO
Published Date :
April 15, 2026, 11:16 p.m.
Last Modified :
April 22, 2026, 8:08 p.m.
Remotely Exploit :
Yes !
Source :
[email protected]
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 3.1 | HIGH | [email protected] | ||||
| CVSS 4.0 | HIGH | [email protected] |
Solution
- Upgrade Pillow to a version that limits GZIP data.
- Do not open FITS files if upgrading is not possible.
- Apply vendor patches as soon as they become available.
Public PoC/Exploit Available at Github
CVE-2026-40192 has a 4 public
PoC/Exploit available at Github.
Go to the Public Exploits tab to see the list.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-40192.
| URL | Resource |
|---|---|
| https://github.com/python-pillow/Pillow/commit/3cb854e8b2bab43f40e342e665f9340d861aa628 | Patch |
| https://github.com/python-pillow/Pillow/pull/9521 | Issue Tracking Patch |
| https://github.com/python-pillow/Pillow/security/advisories/GHSA-whj4-6x5x-4v2j | Mitigation Patch Vendor Advisory |
| https://pillow.readthedocs.io/en/stable/releasenotes/12.2.0.html#prevent-fits-decompression-bomb | Release Notes |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-40192 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-40192
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
None
Dockerfile Python
None
Shell COBOL Dockerfile Go JavaScript Python HTML Ruby PLpgSQL TypeScript
MVidarr - The Music Video Management System
HTML Python Shell JavaScript CSS TypeScript Batchfile Dockerfile Mako Go Template
DSA and DLA for Debian last 14 days
Python
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-40192 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-40192 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
Initial Analysis by [email protected]
Apr. 22, 2026
Action Type Old Value New Value Added CVSS V3.1 AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H Added CPE Configuration OR *cpe:2.3:a:python:pillow:*:*:*:*:*:*:*:* versions from (including) 10.3.0 up to (excluding) 12.2.0 Added Reference Type GitHub, Inc.: https://github.com/python-pillow/Pillow/commit/3cb854e8b2bab43f40e342e665f9340d861aa628 Types: Patch Added Reference Type GitHub, Inc.: https://github.com/python-pillow/Pillow/pull/9521 Types: Issue Tracking, Patch Added Reference Type GitHub, Inc.: https://github.com/python-pillow/Pillow/security/advisories/GHSA-whj4-6x5x-4v2j Types: Mitigation, Patch, Vendor Advisory Added Reference Type GitHub, Inc.: https://pillow.readthedocs.io/en/stable/releasenotes/12.2.0.html#prevent-fits-decompression-bomb Types: Release Notes -
New CVE Received by [email protected]
Apr. 15, 2026
Action Type Old Value New Value Added Description 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. Added CVSS V4.0 AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X Added CWE CWE-400 Added CWE CWE-770 Added Reference https://github.com/python-pillow/Pillow/commit/3cb854e8b2bab43f40e342e665f9340d861aa628 Added Reference https://github.com/python-pillow/Pillow/pull/9521 Added Reference https://github.com/python-pillow/Pillow/security/advisories/GHSA-whj4-6x5x-4v2j Added Reference https://pillow.readthedocs.io/en/stable/releasenotes/12.2.0.html#prevent-fits-decompression-bomb