Pillow: Heap out-of-bounds write in Pillow `ImageFilter.RankFilter` via integer overflow in `ImagingExpand`
At a glance
Severity
HIGH 8.2
EPSS
EPSS 0.45 % · percentile 39 (2026-10-27)
State
PUBLISHED
Published
Updated
Assigner
GitHub_M
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.
GHSA-xj96-63gp-2gmr — Pillow: Heap out-of-bounds write in `ImageFilter.RankFilter` via integer overflow in `ImagingExpand`
PYSEC-2026-3454 — 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 f
