CVE-2026-59197 | Pillow is a Python imaging library. Prior to 12.3.0, Pillow'… | CVSS 8.2 HIGH

Description

Pillow is a Python imaging library. Prior to 12.3.0, Pillow's public rank-filter API can trigger a native heap out-of-bounds write when given a very large odd filter size because ImageFilter.RankFilter.filter() calls image.expand(size // 2, size // 2) before rank-filter size validation and ImagingExpand() computes output dimensions with unchecked signed int arithmetic. This issue is fixed in version 12.3.0.

Metadata

CVE ID: CVE-2026-59197
State: PUBLISHED
Assigner: GitHub_M
Reserved: 2026-07-02 19:53 UTC
Published: 2026-07-14 16:25 UTC
Last updated: 2026-07-14 16:25 UTC
Primary CWE: CWE-787
CWE-787: Out-of-bounds Write
Vendor / Product: python-pillow / Pillow
Sources: cve.org · NVD

Severity & Metrics

8.2 HIGH CVSS 3.1

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

Affected products (1)

Vendor	Product	Platform	Versions
python-pillow	Pillow	—	< 12.3.0

Weakness (CWE)

CWE	Source	Description
CWE-190	cna	CWE-190: Integer Overflow or Wraparound
CWE-787	cna	CWE-787: Out-of-bounds Write

CVSS scores (1)

Score	Severity	Version	Source	Vector
8.2	HIGH	3.1	cna	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:H

References (4)

https://github.com/python-pillow/Pillow/security/advisories/GHSA-xj96-63gp-2gmr https://github.com/python-pillow/Pillow/security/advisories/GHSA-xj96-63gp-2gmr
https://github.com/python-pillow/Pillow/pull/9695 https://github.com/python-pillow/Pillow/pull/9695
https://github.com/python-pillow/Pillow/commit/cce3bdb867c77a3420261ed1bfdb6b0787ec8fc1 https://github.com/python-pillow/Pillow/commit/cce3bdb867c77a3420261ed1bfdb6b0787ec8fc1
https://github.com/python-pillow/Pillow/releases/tag/12.3.0 https://github.com/python-pillow/Pillow/releases/tag/12.3.0