dbcve.org
PillowApplication · Python

CVE-2026-59205

HIGH · 7.5 CVSS v3.1 Published 2026-07-14
Fix available
A fix is available. Upgrade to 12.3.0 or later.
See remediation →
84/100
Remediation priority · High
Remotely reachable No privileges Zero-click 5 weeks old

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
Pillow is a Python imaging library. Prior to 12.3.0, Pillow's ImageCms.ImageCmsTransform.apply(im, imOut) API can trigger controlled native heap corruption when the caller supplies an output image whose mode does not match the transform's declared output mode. This issue is fixed in version 12.3.0.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

The ImageCms.ImageCmsTransform.apply() method in Pillow prior to 12.3.0 suffers from a heap corruption vulnerability when the caller provides an output image whose mode does not match the transform's declared output mode. This mismatch causes controlled native heap corruption, potentially allowing arbitrary code execution.

MitigationUpgrade Pillow to version 12.3.0 or later. Additionally, ensure that output images passed to apply() have modes matching the transform's declared output mode.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
PillowApplication
Affected:< 12.3.0

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Check installed Pillow version
    Run 'pip show pillow' or 'python -c "import PIL; print(PIL.__version__)"' to get the version number
    Affected if Version is lower than 12.3.0 (e.g., 12.2.0, 12.1.0, etc.)
  2. Verify ImageCms module is in use
    Search codebase for 'import ImageCms' or 'from PIL import ImageCms' statements, and grep for 'ImageCmsTransform' class usage
    Affected if Code imports or uses PIL.ImageCms module with ImageCmsTransform class
  3. Identify apply() method calls
    Search for '.apply(' invocations on ImageCmsTransform objects in the codebase
    Affected if Code calls the apply() method on ImageCmsTransform instances
  4. Check output image mode handling
    Review code paths where apply() is called and inspect how the output image is created - verify if its mode (e.g., 'RGB', 'L', 'RGBA') matches the transform's declared output mode (check transform profiles or .transforms output mode)
    Affected if Output image passed to apply() has a mode different from the transform's declared output mode

You are affected if Pillow version is below 12.3.0 AND your code uses ImageCmsTransform.apply() with an output image whose mode does not match the transform's declared output mode.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Upgrade available Upgrade to 12.3.0 or later
Fixed in 12.3.0
Interim mitigation

Upgrade Pillow to version 12.3.0 or later. Additionally, ensure that output images passed to apply() have modes matching the transform's declared output mode.

Recommended fix High confidence

Pillow 12.3.0

  1. Check current Pillow version by running: pip show pillow
  2. Upgrade Pillow to version 12.3.0 using: pip install --upgrade Pillow==12.3.0
  3. Verify the upgrade was successful by running: pip show pillow and confirming the version is 12.3.0
  4. If using a requirements file, update the Pillow entry to: Pillow==12.3.0
  5. If using Poetry, run: poetry add [email protected]
  6. If using Conda, run: conda install pillow=12.3.0

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Pillow Scoped from the published advisory
  • Consultation2.0 h
  • Implementation1.0 h
  • Testing3.0 h
  • Review / QA1.0 h
7.0 hours of engineering $1,210
Get the upgrade done

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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2026-59205 in production — separate from our analysis above.

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