An attacker who uses this vulnerability can craft a PDF which leads to large memory usage. This requires opening a file with cross-reference streams.
This has been fixed in pypdf==6.21.3.
If you cannot upgrade yet, consider applying the changes from PR #4269.
{
"cwe_ids": [
"CWE-400",
"CWE-770"
],
"github_reviewed": true,
"github_reviewed_at": "2026-10-30T23:07:28Z",
"nvd_published_at": "2026-10-29T21:17:20Z",
"severity": "HIGH"
}