Pillow: TarIO negative size field causes infinite CPU-spin loop

影響: pip:Pillow < 13.0.0 → 13.0.0

TarIO.__init__ does not check that a tar header's size field is positive. A crafted header with a negative size makes it seek backward onto itself. This causes an infinite loop that uses 100% CPU and never returns. Details TarIO.__init__ reads 512-byte tar headers one at a time, looking for a member with a given name. For each header it reads the size field and skips ahead to the next header: python size = int(s[124:135], 8) ... self.fh.seek((size + 511) & (~511), io.SEEK_CUR) There is no check…

GitHub Advisory Databaseで読む

2026/10/23 01:01、GitHub Advisory Databaseが「Pillow: TarIO negative size field causes infinite CPU-spin loop」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-2026-96642。