{"id":"BIT-pillow-2026-96641","summary":"Pillow: Reachable undefined behavior in native integer operations, potentially leading to denial of service or logic integrity compromise","details":"Pillow is a Python imaging library. Prior to 13.0.0, PILfont text-width accumulation in src/_imaging.c checks positive glyph advances against INT_MAX but does not check negative advances against INT_MIN. Repeating a signed 16-bit advance of -32768 can therefore execute a signed C integer overflow in xsize += dx, producing a large positive width from a negative mathematical result. Applications that use getlength(), getsize(), or derived layout, quota, serialization, or allocation calculations can experience logic-integrity errors or resource consumption, while the high-level mask path commonly retains a decompression-bomb check. This issue is fixed in version 13.0.0.","aliases":["CVE-2026-96641","GHSA-4rm8-3hmm-39fg","PYSEC-2026-4340"],"modified":"2026-10-29T10:56:07.449486409Z","published":"2026-10-29T08:58:16.836Z","database_specific":{"severity":"Medium","cpes":["cpe:2.3:a:python:pillow:*:*:*:*:*:python:*:*"]},"references":[{"type":"FIX","url":"https://github.com/python-pillow/Pillow/commit/80de4be9e38d3a6148dd4d8491eb80cd12b760a4"},{"type":"REPORT","url":"https://github.com/python-pillow/Pillow/pull/10010"},{"type":"ARTICLE","url":"https://github.com/python-pillow/Pillow/releases/tag/13.0.0"},{"type":"ADVISORY","url":"https://github.com/python-pillow/Pillow/security/advisories/GHSA-4rm8-3hmm-39fg"},{"type":"WEB","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-96641"}],"affected":[{"package":{"name":"pillow","ecosystem":"Bitnami","purl":"pkg:bitnami/pillow"},"ranges":[{"type":"SEMVER","events":[{"introduced":"0"},{"fixed":"13.0.0"}]}],"database_specific":{"source":"https://github.com/bitnami/vulndb/tree/main/data/pillow/BIT-pillow-2026-96641.json"},"severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H"}]}],"schema_version":"1.9.2"}