An attacker who uses this vulnerability can craft a PDF which leads to large memory usage. This requires parsing content streams with many small operations.
This has been fixed in pypdf==6.21.0.
If you cannot upgrade yet, consider applying the changes from PR #4218.
{
"cwe_ids": [
"CWE-400",
"CWE-770"
],
"github_reviewed": true,
"github_reviewed_at": "2026-10-22T16:49:22Z",
"nvd_published_at": "2026-10-21T16:17:27Z",
"severity": "MODERATE"
}