CVE-2026-84311 pypdf: Possible long runtimes/large memory usage when extracting XForm objects

pypdf is a free and open-source pure-python PDF library. Prior to 6.16.1, an attacker can craft a PDF that causes pypdf/page.py PageObject.extracttext and PageObject.extractxformtext to traverse a directed acyclic graph of reused form XObjects in which each form invokes a child multiple times,...