CVE-2026-59205Public exploitNetwork attack vector

Process crash via unchecked output mode mismatch

Published Jul 14, 2026 · Updated Jul 14, 2026

Out-of-bounds write in Pillow's ImageCmsTransform.apply before 12.3.0 allows remote attackers to corrupt heap memory via a mode mismatch. The method checks image dimensions but passes a caller-supplied output row to LittleCMS, which writes four-byte RGBA pixels into a one-byte L-mode row. Exploitation requires an application to let untrusted users control transform parameters or the output image and can crash the process.

CVSS severity7.5
High
EPSS probability0.39%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Out-of-bounds write in Pillow's ImageCmsTransform.apply before 12.3.0 allows remote attackers to corrupt heap memory via a mode mismatch. The method checks image dimensions but passes a caller-supplied output row to LittleCMS, which writes four-byte RGBA pixels into a one-byte L-mode row. Exploitation requires an application to let untrusted users control transform parameters or the output image and can crash the process.

The record

CVE
CVE-2026-59205
Published
Jul 14, 2026
Updated
Jul 14, 2026
Vendor
Pillow
Product
Pillow
Classifications
CWE-787, T1499
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jul 14, 2026CVE publishedPublication date reported by the CVE source.
  2. Jul 14, 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=< 12.3.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Pillow · Pillowversion=< 12.3.0

Published CVSS scores

7.5GitHub, Inc.CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

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.

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No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-787Out-of-bounds Write
T1499Endpoint Denial of Service

Public exploit references

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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