High severity · published Jul 14, 2026
CVE-2026-59205
Pillow: Controlled heap out-of-bounds write in `ImageCmsTransform.apply()` via output mode mismatch
7.5
CVSS
0.4%
EPSS
No
On KEV
Description
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.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Confidentiality
None
Integrity
None
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.4% · higher than 32% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
PI
Pillow · python-pillow
< 12.3.0 · source: vendor, NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-59205
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-59205
Patch
https://github.com/python-pillow/Pillow/commit/a9ffc42bedf4fc0a7ef8d6486e7f9e81e3397721
Issue Tracking
https://github.com/python-pillow/Pillow/pull/9715
Release Notes
https://github.com/python-pillow/Pillow/releases/tag/12.3.0
Exploit
https://github.com/python-pillow/Pillow/security/advisories/GHSA-9hw9-ch79-4vh6
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