CVE-2026-55380 — Security Box Score

CVE · referencelatest edition

Reference page — cumulative record through Wednesday, August 19, 2026 UTC. Reference pages update as the archive grows; only dated daily editions are immutable pages of record.

CVE-2026-55380HIGH

python-pillow Pillow — Pillow GdImageFile decompression bomb protection bypass

  AV  AC  PR  UI  S  C  I  A   CVSS    EPSS   %ile   KEV
   N   L   N   N  U  N  N  H    7.5   .0042   35.0     —

AFFECTED
  Product  Versions    Fixed
  Pillow   < 12.3.0 –  —

TIMELINE
  Jun 16  Reserved by GitHub_M
  Jul 6   EXPLOIT PUBLISHED — CVE-2026-55380 (python-pillow Pillow). Public exploit reference added.
  Jul 6   Published (CNA: GitHub_M)

CWE-789 · CNA: GitHub_M · CVSS v3.1 · 3 references · NVD status: Analyzed

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.

Lifecycle

Complete event history — 3 events, chronological
Date	Event	Detail
June 16, 2026	Reserved	Reserved by GitHub_M
July 6, 2026	EXPLOIT PUBLISHED	EXPLOIT PUBLISHED — CVE-2026-55380 (python-pillow Pillow). Public exploit reference added.
July 6, 2026	Published	Published (CNA: GitHub_M)

Affected

Affected products and packages — 1 row
Vendor	Product / Package	Ecosystem	Version introduced	Fixed
python-pillow	Pillow	—	< 12.3.0	—

Weaknesses

CWE-789

References (3)

https://github.com/python-pillow/Pillow/blob/main/docs/releasenotes/12.3.0.rst [Release Notes]
https://github.com/python-pillow/Pillow/commit/f39b0ae6624eb2d7c5c5d651d9bb5fdbd96a8675 [Patch]
https://github.com/python-pillow/Pillow/security/advisories/GHSA-phj9-mv4w-65pm [Exploit, Vendor Advisory]

Authoritative record: CVE-2026-55380 at cve.org

Vendors: python-pillow

Weaknesses: CWE-789

About this page

This is a reference page, not a dated page of record. It assembles the complete lifecycle of CVE-2026-55380 from the CVE Program record, NVD enrichment, the CISA KEV catalog, EPSS, and OSV advisories. The box score's numbers (CVSS, EPSS, KEV status) are current as of Wednesday, August 19, 2026 UTC and are re-derived as the archive grows; only dated daily editions are immutable pages of record. The authoritative source for this identifier is cve.org.