CVE-2026-55380

Pillow GdImageFile decompression bomb protection bypass

Description

Pillow is a Python imaging library. Prior to 12.3.0, PIL/GdImageFile.py GdImageFile._open() read image dimensions from the GD 2.x header and stored them in self._size without calling Image._decompression_bomb_check(), allowing a crafted .gd file to trigger excessive C-heap allocation when loaded. This issue is fixed in version 12.3.0.

Scores

Weaknesses (CWE)

• CWE-789

Advisories

• GHSA-phj9-mv4w-65pm — Pillow `GdImageFile._open()`: image dimensions accepted without `_decompression_bomb_check()`
• PYSEC-2026-2256 — Pillow is a Python imaging library. Prior to 12.3.0, PIL/GdImageFile.py GdImageFile._open() read image dimensions from the GD 2.x header and stored them in self

European references

• ENISA EUVD · EUVD-2026-41901
• GCVE · GCVE-0-2026-55380

CERT-FR advisories

• CERTFR-2026-AVI-1366 — Multiples vulnérabilités dans les produits Splunk · cert.ssi.gouv.fr
• CERTFR-2026-AVI-1094 — Multiples vulnérabilités dans les produits IBM · cert.ssi.gouv.fr

Affected configurations (NVD CPE)

• cpe:2.3:a:python:pillow:*:*:*:*:*:*:*:* < 12.3.0

Affected products

References

• https://github.com/python-pillow/Pillow/security/advisories/GHSA-phj9-mv4w-65pm
• https://github.com/python-pillow/Pillow/commit/f39b0ae6624eb2d7c5c5d651d9bb5fdbd96a8675
• https://github.com/python-pillow/Pillow/blob/main/docs/releasenotes/12.3.0.rst

Sources