Pillow has a heap buffer overflow with nested list coordinates
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 was introduced in Pillow 11.2.1.
Affected software
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| Platform | Package | Vulnerable versions | Fixed in |
|---|---|---|---|
| Python (PyPI) | pillow | >= 11.2.1, < 12.2.0 | 12.2.0 |
References
- https://github.com/python-pillow/Pillow/releases/tag/12.2.0
- https://github.com/python-pillow/Pillow/security/advisories/GHSA-5xmw-vc9v-4wf2
- https://nvd.nist.gov/vuln/detail/CVE-2026-42309
- https://github.com/python-pillow/Pillow
- https://github.com/designcomputer/mysql_mcp_server/commit/a96549f4a4d65443fd6e9c7f2324fba9a5c80a82
- https://github.com/python-pillow/Pillow/commit/cf6de8ca9b23e714aa5310e1c791eda66fc0b670
- https://github.com/pypa/advisory-database/tree/main/vulns/pillow/PYSEC-2026-2251.yaml
- CVSS vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H- Weakness (CWE)
CWE-122- Platform
- Python (PyPI)
- Package
pillow- Disclosed
- 04.05.2026
- Updated
- 19.10.2026 22:17
Sources and licenses
OSV / GitHub Advisory Database - PYSEC-2026-2251 - PyPA Advisory Database; CC BY 4.0
OSV / GitHub Advisory Database - GHSA-5xmw-vc9v-4wf2 - CC BY 4.0
Vulnerability history: pillow
All published vulnerabilities of this package (Python (PyPI)), newest first. Shows whether this is a one-off slip or a package that needs watching.
- Total entries
- 89
- First → latest
- 04.2014 10.2026
- Without a fix
- 0
- Exploited in attacks
- 1
Severity breakdown
- Critical 12
- High 57
- Medium 18
- Low 1
- Unrated 1
Disclosures per year
- 2017: 1
- 2018: 0
- 2019: 1
- 2020: 10
- 2021: 20
- 2022: 8
- 2023: 3
- 2024: 2
- 2025: 1
- 2026: 31
earlier: 12
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Pillow has a heap buffer overflow with nested list coordinates this entry
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