# CVE-2026-42309: pillow: Pillow is a Python imaging library

CVE-2026-42309 is fixed in 3 products on 1 platform, first by python3-pil 11.3.0-1ubuntu1.3, released May 8, 2026. It is not reported as exploited. Patch Radar priority: Routine.

- Web page: https://patchblox.com/security/cve/CVE-2026-42309
- Priority: Routine
- CVSS: 5.5 (medium)
- EPSS: 0.0013
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: May 8, 2026

## 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.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | pillow Debian 14 | 12.2.0-1 | [DEBIAN-CVE-2026-42309](https://patchblox.com/security/data/fix/linux/debian-cve-2026-42309.md) | May 15, 2026 |
| Linux | python3-pil Ubuntu 25.10 (questing) | 11.3.0-1ubuntu1.3 | [python3-pil 11.3.0-1ubuntu1.3](https://patchblox.com/security/data/fix/linux/ubuntu-questing-python3-pil-11.3.0-1ubuntu1.3.md) | May 8, 2026 |
| Linux | python3-pil Ubuntu 26.04.1 LTS (resolute) | 12.1.1-2ubuntu1.2 | [python3-pil 12.1.1-2ubuntu1.2](https://patchblox.com/security/data/fix/linux/ubuntu-resolute-python3-pil-12.1.1-2ubuntu1.2.md) | May 8, 2026 |
| Linux | python3-pil.imagetk Ubuntu 25.10 (questing) | 11.3.0-1ubuntu1.3 | [python3-pil.imagetk 11.3.0-1ubuntu1.3](https://patchblox.com/security/data/fix/linux/ubuntu-questing-python3-pil.imagetk-11.3.0-1ubuntu1.3.md) | May 8, 2026 |
| Linux | python3-pil.imagetk Ubuntu 26.04.1 LTS (resolute) | 12.1.1-2ubuntu1.2 | [python3-pil.imagetk 12.1.1-2ubuntu1.2](https://patchblox.com/security/data/fix/linux/ubuntu-resolute-python3-pil.imagetk-12.1.1-2ubuntu1.2.md) | May 8, 2026 |

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Data as of 2026-11-09T01:18:40Z UTC. Source: Patchblox Patch Radar (https://patchblox.com/security/patch-radar). Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo

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