Pillow PDF append accepts malformed shared page-tree DAG causing resource exhaustion

影響: pip:Pillow >= 5.1.0, < 13.0.0 → 13.0.0

Pillow's documented PDF append path can spend disproportionate CPU time on a compact malformed PDF page tree. An attacker who can supply an existing PDF to an application that appends an image with Image.save(..., format="PDF", append=True) can provide a malformed /Pages tree where each level repeats the same child /Pages reference in /Kids. Pillow treats the graph as a tree and expands each repeated reference in PdfParser.linearize_page_tree() without tracking visited or duplicate indirect ref…

GitHub Advisory Databaseで読む

2026/10/23 01:00、GitHub Advisory Databaseが「Pillow PDF append accepts malformed shared page-tree DAG causing resource exhaustion」を公開しました (種別: 脆弱性アドバイザリ)。重大度は「重要」(high) です。関連する技術: Python。CVE: CVE-2026-96640。