CVE-2026-42309

Description

Pillow is a Python imaging library. From version 11.2.1 to before version 12.2.0, passing nested lists as coordinates to APIs that accept coordinates such as ImagePath.Path, ImageDraw.ImageDraw.polygon and ImageDraw.ImageDraw.line could cause a heap buffer overflow, as nested lists were recursively unpacked beyond the allocated buffer. Coordinate lists are now validated to contain exactly two numeric coordinates. This issue has been patched in version 12.2.0.

How to fix CVE-2026-42309

To remediate CVE-2026-42309, upgrade the affected package to a fixed version below.

• —upgrade to 12.2.0 or later
• —upgrade to 12.2.0-1 or later
• —upgrade to 12.2.0 or later

Is CVE-2026-42309 being exploited?

Low — EPSS is 0.0%, meaning exploitation activity has not been observed at scale.

Affected packages (3)

• >= 11.2.1, < 12.2.0
• from 0, < 12.2.0-1
• >= 11.2.1, < 12.2.0

CVSS scores

References (5)

• ADVISORYnvd.nist.gov/vuln/detail/CVE-2026-42309
• ADVISORYsecurity-tracker.debian.org/tracker/CVE-2026-42309
• PATCHgithub.com/python-pillow/Pillow
• WEBgithub.com/python-pillow/Pillow/releases/tag/12.2.0
• WEB