{"id":"CVE-2026-112399","title":"Pillow: APNG background disposal allocates full canvas before decompression bomb check","summary":"Pillow is a Python imaging library. From 8.1.0 until 13.0.0, Pillow can allocate an APNG disposal background at the full canvas size before applying the decompression-bomb check. A crafted APNG with a small first frame, a very large decl…","severity":"high","cvss":8.7,"cvssVector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N","cvssSource":"cna","cwe":["CWE-789"],"vendor":"python-pillow","product":"Pillow","affected":["Pillow >= 8.1.0, < 13.0.0"],"published":"2026-10-19","updated":"2026-10-19","sourceUpdated":"2026-10-19T21:10:11.266Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-112399","references":[{"url":"https://github.com/python-pillow/Pillow/security/advisories/GHSA-5xm2-6676-qcp9","label":"https://github.com/python-pillow/Pillow/security/advisories/GHSA-5xm2-6676-qcp9"},{"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":"2026-10-19T21:43:56.128Z","slug":"CVE-2026-112399","body":"## Overview\n\nPillow is a Python imaging library. From 8.1.0 until 13.0.0, Pillow can allocate an APNG disposal background at the full canvas size before applying the decompression-bomb check. A crafted APNG with a small first frame, a very large declared canvas, and background disposal or first-frame OP_PREVIOUS reaches PngImageFile._seek while Image.open() positions frame zero. The full-canvas allocation occurs inside Image.open() without requiring pixel loading or frame iteration. This can exhaust memory and deny service. This issue is fixed in version 13.0.0.\n\n## Affected\n\n- `Pillow >= 8.1.0, < 13.0.0`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"twilight","depthScore":48,"depthScoreParts":{"impact":47.8,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}