CVE-2026-55380 | Pillow is a Python imaging library. Prior to 12.3.0, PIL/GdI… | CVSS 7.5 HIGH

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.

Metadata

CVE ID: CVE-2026-55380
State: PUBLISHED
Assigner: GitHub_M
Reserved: 2026-06-16 18:57 UTC
Published: 2026-07-06 18:50 UTC
Last updated: 2026-07-06 19:23 UTC
Primary CWE: CWE-789
CWE-789: Memory Allocation with Excessive Size Value
Vendor / Product: python-pillow / Pillow
Sources: cve.org · NVD

Severity & Metrics

7.5 HIGH CVSS 3.1

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

SSVC — CISA Coordinator

Exploitation: PoC
Automatable: yes
Tech. Impact: partial

Affected products (1)

Vendor	Product	Platform	Versions
python-pillow	Pillow	—	< 12.3.0

Weakness (CWE)

CWE	Source	Description
CWE-789	cna	CWE-789: Memory Allocation with Excessive Size Value

CVSS scores (1)

Score	Severity	Version	Source	Vector
7.5	HIGH	3.1	cna	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

References (3)

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