CVE-2026-59197
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.
Weakness
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.
Affected products
- python pillow
References
- https://github.com/python-pillow/Pillow/commit/cce3bdb867c77a3420261ed1bfdb6b0787ec8fc1
- https://github.com/python-pillow/Pillow/pull/9695
- https://github.com/python-pillow/Pillow/releases/tag/12.3.0
- https://github.com/python-pillow/Pillow/security/advisories/GHSA-xj96-63gp-2gmr
- https://github.com/python-pillow/Pillow/security/advisories/GHSA-xj96-63gp-2gmr
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