CVE-2026-59197 — 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-2026-59197HIGH

python-pillow Pillow — Pillow: Heap out-of-bounds write in Pillow `ImageFilter.RankFilter` via integer overflow in `ImagingExpand`

  AV  AC  PR  UI  S  C  I  A   CVSS    EPSS   %ile   KEV
   N   L   N   N  U  N  L  H    8.2   .0044   36.5     —

AFFECTED
  Product  Versions    Fixed
  Pillow   < 12.3.0 –  —

TIMELINE
  Jul 2   Reserved by GitHub_M
  Jul 14  EXPLOIT PUBLISHED — CVE-2026-59197 (python-pillow Pillow). Public exploit reference added.
  Jul 14  Published (CNA: GitHub_M)
  Jul 21  EXPLOIT PUBLISHED — CVE-2026-59197 (python-pillow Pillow). Public exploit reference added.

CWE-190, CWE-787 · CNA: GitHub_M · CVSS v3.1 · 4 references · NVD status: Modified

Description

Pillow is a Python imaging library. Prior to 12.3.0, Pillow's public rank-filter API can trigger a native heap out-of-bounds write when given a very large odd filter size because ImageFilter.RankFilter.filter() calls image.expand(size // 2, size // 2) before rank-filter size validation and ImagingExpand() computes output dimensions with unchecked signed int arithmetic. This issue is fixed in version 12.3.0.

Lifecycle

Complete event history — 4 events, chronological
Date	Event	Detail
July 2, 2026	Reserved	Reserved by GitHub_M
July 14, 2026	EXPLOIT PUBLISHED	EXPLOIT PUBLISHED — CVE-2026-59197 (python-pillow Pillow). Public exploit reference added.
July 14, 2026	Published	Published (CNA: GitHub_M)
July 21, 2026	EXPLOIT PUBLISHED	EXPLOIT PUBLISHED — CVE-2026-59197 (python-pillow Pillow). Public exploit reference added.

Affected

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

Weaknesses

CWE-190 · CWE-787

References (4)

https://github.com/python-pillow/Pillow/commit/cce3bdb867c77a3420261ed1bfdb6b0787ec8fc1 [Patch]
https://github.com/python-pillow/Pillow/pull/9695 [Issue Tracking, Patch]
https://github.com/python-pillow/Pillow/releases/tag/12.3.0 [Release Notes]
https://github.com/python-pillow/Pillow/security/advisories/GHSA-xj96-63gp-2gmr [Exploit, Vendor Advisory]

Authoritative record: CVE-2026-59197 at cve.org

Vendors: python-pillow

Weaknesses: CWE-190 · CWE-787

About this page

This is a reference page, not a dated page of record. It assembles the complete lifecycle of CVE-2026-59197 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.