An attacker who uses this vulnerability can craft a PDF which leads to long runtimes. This requires cross-reference streams with wrong large /Size values or object streams with wrong large /N values.
This has been fixed in pypdf==6.10.1.
If you cannot upgrade yet, consider applying the changes from PR #3733.
{
"github_reviewed": true,
"cwe_ids": [
"CWE-834"
],
"github_reviewed_at": "2026-04-15T19:43:09Z",
"nvd_published_at": "2026-04-22T21:17:09Z",
"severity": "MODERATE"
}