{"id":"CVE-2026-96640","revision":"ba98954d97ec4f16a04cdf2b40746014","records":[{"revision":"ba98954d97ec4f16a04cdf2b40746014","observedAt":"2026-10-23T15:48:27.903+00:00","statement":{"source":"cve-program","id":"CVE-2026-96640","aliases":[],"title":"Pillow PDF append accepts malformed shared page-tree DAG causing resource exhaustion","description":"Pillow is a Python imaging library. From 5.1.0 until 13.0.0, PdfParser.linearize_page_tree() in src/PIL/PdfParser.py treats a PDF /Pages graph as a tree without tracking duplicate indirect references. When Image.save(..., format=\"PDF\", append=True) processes an attacker-controlled existing PDF whose /Kids arrays repeatedly reference the same child /Pages node, Pillow expands the shared subtree as distinct pages. A compact malformed PDF can therefore create exponentially many page references and consume disproportionate CPU before the append completes. This issue is fixed in version 13.0.0.","state":0,"publishedAt":"2026-10-21T21:03:22.785+00:00","modifiedAt":"2026-10-21T21:03:22.785+00:00","affected":[{"ecosystem":"Vendor product","name":"Pillow","ranges":[],"versions":[],"rawVersionEvidence":"{\n                    \"vendor\": \"python-pillow\",\n                    \"product\": \"Pillow\",\n                    \"versions\": [\n                        {\n                            \"version\": \">= 5.1.0, < 13.0.0\",\n                            \"status\": \"affected\"\n                        }\n                    ]\n                }"}],"metrics":[{"system":"CVSS 4.0","vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N","score":8.2,"severity":"HIGH"}],"references":["https://github.com/python-pillow/Pillow/security/advisories/GHSA-mrfp-p49p-3hf2","https://github.com/python-pillow/Pillow/pull/10093","https://github.com/python-pillow/Pillow/commit/6f0e7ee1f9c2fe227906f8a4b926e6622b702bc7","https://github.com/python-pillow/Pillow/releases/tag/13.0.0"],"sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-96640","license":"CVE Program Terms of Use","key":"cve-program:CVE-2026-96640","identifiers":["CVE-2026-96640"]},"retained":false,"historicalAffected":[]}],"coverage":[]}