CVE-2026-119205

The pypdf pure-python PDF library is vulnerable to an infinite loop in versions prior to 6.21.4 . The root cause is that when cloning or duplicating a crafted cyclic DictionaryObject , the clone traversal incorrectly checked generated destination references instead of the original source referenc...

CVE-2026-119205 pypdf: Possible infinite loop when cloning dictionaries

pypdf is a free and open-source pure-python PDF library. Prior to 6.21.4, pypdf can enter an infinite loop when cloning or duplicating a crafted cyclic DictionaryObject. Clone traversal checked generated destination references rather than the original source references, allowing some source cycle...