{"id":"CVE-2026-96636","title":"Pillow: Decompression-bomb protection bypass via multi-frame seek() in MPO and DCX (MpoImageFile.seek / DcxImageFile.seek)","summary":"Pillow is a Python imaging library. Prior to 13.0.0, MpoImageFile.seek() and DcxImageFile.seek() reparse later MPO or DCX frames and replace self._size without rerunning Image._decompression_bomb_check(). A crafted multi-frame image can …","severity":"medium","cvss":6.5,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H","cvssSource":"cna","cwe":["CWE-400","CWE-409"],"vendor":"python-pillow","product":"Pillow","affected":["Pillow < 13.0.0"],"published":"2026-10-21","updated":"2026-10-21","sourceUpdated":"2026-10-21T21:05:20.850Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-96636","references":[{"url":"https://github.com/python-pillow/Pillow/security/advisories/GHSA-p8hx-v2p6-rp84","label":"https://github.com/python-pillow/Pillow/security/advisories/GHSA-p8hx-v2p6-rp84"},{"url":"https://github.com/python-pillow/Pillow/pull/10011","label":"https://github.com/python-pillow/Pillow/pull/10011"},{"url":"https://github.com/python-pillow/Pillow/commit/f1acfc54c53502948d0d14121872061df931db48","label":"https://github.com/python-pillow/Pillow/commit/f1acfc54c53502948d0d14121872061df931db48"},{"url":"https://github.com/python-pillow/Pillow/releases/tag/13.0.0","label":"https://github.com/python-pillow/Pillow/releases/tag/13.0.0"}],"tags":["cve.org"],"ingestedAt":"2026-10-21T22:18:33.757Z","slug":"CVE-2026-96636","body":"## Overview\n\nPillow is a Python imaging library. Prior to 13.0.0, MpoImageFile.seek() and DcxImageFile.seek() reparse later MPO or DCX frames and replace self._size without rerunning Image._decompression_bomb_check(). A crafted multi-frame image can use a tiny first frame to pass Image.open() and then declare an over-limit later frame. Normal frame iteration through seek(), load(), or ImageSequence.Iterator can decode that frame and commit hundreds of megabytes or more, causing memory-exhaustion denial of service. This issue is fixed in version 13.0.0.\n\n## Affected\n\n- `Pillow < 13.0.0`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"sunlit","depthScore":36,"depthScoreParts":{"impact":35.8,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}