{"schema_version":"1.9.0","id":"BIT-pillow-2026-59197","published":"2026-07-19T23:50:18.914Z","modified":"2026-09-08T08:48:18.503515545Z","aliases":["CVE-2026-59197","GHSA-xj96-63gp-2gmr","PYSEC-2026-3454"],"summary":"Pillow: Heap out-of-bounds write in Pillow `ImageFilter.RankFilter` via integer overflow in `ImagingExpand`","details":"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":[{"package":{"name":"pillow","ecosystem":"Bitnami","purl":"pkg:bitnami/pillow"},"ranges":[{"type":"SEMVER","events":[{"introduced":"0"},{"fixed":"12.3.0"}]}],"database_specific":{"source":"https://github.com/bitnami/vulndb/tree/main/data/pillow/BIT-pillow-2026-59197.json"},"severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:H"}]}],"references":[{"type":"FIX","url":"https://github.com/python-pillow/Pillow/commit/cce3bdb867c77a3420261ed1bfdb6b0787ec8fc1"},{"type":"FIX","url":"https://github.com/python-pillow/Pillow/pull/9695"},{"type":"ARTICLE","url":"https://github.com/python-pillow/Pillow/releases/tag/12.3.0"},{"type":"ADVISORY","url":"https://github.com/python-pillow/Pillow/security/advisories/GHSA-xj96-63gp-2gmr"},{"type":"WEB","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-59197"}],"database_specific":{"cpes":["cpe:2.3:a:python:pillow:*:*:*:*:*:python:*:*"],"severity":"High"}}