An attacker who uses this vulnerability can craft a PDF which leads to an infinite loop. This requires accessing the children of a TreeObject, for example as part of outlines.
This has been fixed in pypdf==6.7.1.
If you cannot upgrade yet, consider applying the changes from PR #3645.
{
"nvd_published_at": "2026-02-20T22:16:28Z",
"github_reviewed_at": "2026-02-18T22:40:49Z",
"github_reviewed": true,
"severity": "MODERATE",
"cwe_ids": [
"CWE-835"
]
}