GHSA-6C7F-9265-G8FW pypdf: Possible long runtimes for repeated references to the same missing object

Impact An attacker who uses this vulnerability can craft a PDF which leads to long runtimes. This requires loading relevant parts of a file like their pages where the same, but non-existent indirect object is referenced multiple times. Patches This has been fixed in pypdf==6.21.2. Workarounds If...