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.
This has been fixed in pypdf==6.9.1.
If you cannot upgrade yet, consider applying the changes from PR #3686.
{
"cwe_ids": [
"CWE-400",
"CWE-407"
],
"severity": "MODERATE",
"nvd_published_at": "2026-03-20T10:16:18Z",
"github_reviewed": true,
"github_reviewed_at": "2026-03-18T16:17:31Z"
}