CVE-2026-42309

Pillow: Heap buffer overflow with nested list coordinates

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.

Scores

Weaknesses (CWE)

• CWE-122

Advisories

• GHSA-5xmw-vc9v-4wf2 — Pillow has a heap buffer overflow with nested list coordinates
• PYSEC-2026-2251 — 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 Im

European references

• ENISA EUVD · EUVD-2026-28901
• GCVE · GCVE-0-2026-42309

CERT-FR advisories

• CERTFR-2026-AVI-1366 — Multiples vulnérabilités dans les produits Splunk · cert.ssi.gouv.fr
• CERTFR-2026-AVI-0627 — Multiples vulnérabilités dans les produits Splunk · cert.ssi.gouv.fr

Affected configurations (NVD CPE)

• cpe:2.3:a:python:pillow:*:*:*:*:*:*:*:* ≥ 11.2.1 < 12.2.0

Affected products

References

• https://github.com/python-pillow/Pillow/security/advisories/GHSA-5xmw-vc9v-4wf2
• https://github.com/python-pillow/Pillow/releases/tag/12.2.0

Sources