CVE-2026-59197
Pillow: Heap out-of-bounds write in Pillow `ImageFilter.RankFilter` via integer overflow in `ImagingExpand`
CVSS Score
8.2
EPSS Score
0.0%
EPSS Percentile
0th
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.
| CWE | CWE-787 CWE-190 |
| Vendor | python-pillow |
| Product | pillow |
| Published | Jul 14, 2026 |
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CVSS v3 Breakdown
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:H Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
Low
Availability
High
Affected Versions
python-pillow / Pillow
< 12.3.0
References
github.com: https://github.com/python-pillow/Pillow/security/advisories/GHSA-xj96-63gp-2gmr github.com: https://github.com/python-pillow/Pillow/pull/9695 github.com: https://github.com/python-pillow/Pillow/commit/cce3bdb867c77a3420261ed1bfdb6b0787ec8fc1 github.com: https://github.com/python-pillow/Pillow/releases/tag/12.3.0