CVE-2026-59205

Pillow: Controlled heap out-of-bounds write in `ImageCmsTransform.apply()` via output mode mismatch

HIGH
7.5
CVSS Score
Published: July 14, 2026 at 03:48 PM UTC
Updated: October 24, 2026 at 09:10 PM UTC
2 products affected across 2 vendorsPillowPillow

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Severity
HIGH7.5
Exploit prediction
EPSS 0.4%
SSVC
PoC

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.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

v < 12.3.0
Affected range stops below 12.3.0, so it looks safe — our inference, not a vendor statement
v < 12.3.0
Affected range stops below 12.3.0, so it looks safe — our inference, not a vendor statement

SSVC — Action Prioritization

SSVCPoCAutomatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

7.5HIGHGitHub_M
Attack Vector
NETWORK
Complexity
LOW
Privileges
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
NONE
Availability
HIGH
Vector?

Quick Info

StatusANALYZED
CWE
CWE-787

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