CVE-2026-33123

pypdf is a free and open-source pure-python PDF library. Versions prior to 6.9.1 allow an attacker to craft a malicious PDF which leads to long runtimes and/or large memory usage. Exploitation requires accessing an array-based stream with many entries. This issue has been fixed in version 6.9.1...

pypdf has inefficient decoding of array-based streams

Impact An attacker who uses this vulnerability can craft a PDF which leads to long runtimes and/or large memory usage. This requires accessing an array-based stream with lots of entries. Patches This has been fixed in pypdf==6.9.1. Workarounds If you cannot upgrade yet, consider applying the...