CVE-2026-59197

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.

References

https://github.com/python-pillow/Pillow/security/advisories/GHSA-xj96-63gp-2gmr

https://github.com/python-pillow/Pillow/releases/tag/12.3.0

https://github.com/python-pillow/Pillow/pull/9695

https://github.com/python-pillow/Pillow/commit/cce3bdb867c77a3420261ed1bfdb6b0787ec8fc1

Details

Source: Mitre, NVD

Published: 2026-07-14

Updated: 2026-07-15

Risk Information

CVSS v2

Base Score: 8.5

Vector: CVSS2#AV:N/AC:L/Au:N/C:N/I:P/A:C

Severity: High

CVSS v3

Base Score: 8.2

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

Severity: High

EPSS

EPSS: 0.00397