CVE-2026-40192Network attack vector

Application crash via unbounded FITS decompression

Published Apr 15, 2026 · Updated Apr 15, 2026

Resource exhaustion in Pillow 10.3.0 through 12.1.1 allows remote attackers to crash applications via crafted GZIP-compressed FITS files. The FitsGzipDecoder.decode method passes the entire remaining file stream to gzip.decompress, expanding all compressed payload data in memory rather than reading only the bytes required by the image dimensions. Exploitation requires an application to decode an attacker-supplied FITS file and results in an out-of-memory crash or severe performance degradation.

CVSS severity8.7
High
EPSS probability0.67%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Resource exhaustion in Pillow 10.3.0 through 12.1.1 allows remote attackers to crash applications via crafted GZIP-compressed FITS files. The FitsGzipDecoder.decode method passes the entire remaining file stream to gzip.decompress, expanding all compressed payload data in memory rather than reading only the bytes required by the image dimensions. Exploitation requires an application to decode an attacker-supplied FITS file and results in an out-of-memory crash or severe performance degradation.

The record

CVE
CVE-2026-40192
Published
Apr 15, 2026
Updated
Apr 15, 2026
Vendor
Pillow
Product
Pillow
Classifications
CWE-400, CWE-770, T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Apr 15, 2026CVE publishedPublication date reported by the CVE source.
  2. Apr 15, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=>= 10.3.0, < 12.2.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Pillow · Pillowversion=>= 10.3.0, < 12.2.0

Published CVSS scores

8.7GitHub CNACVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-400Uncontrolled Resource Consumption
CWE-770Allocation of Resources Without Limits or Throttling
T1499.004Endpoint Denial of Service: Application or System Exploitation

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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