An attacker who uses this vulnerability can craft a PDF which leads to long runtimes and large memory consumption. This requires extracting the text of a page with lots of XForm objects, where some of them might be re-used.
This has been fixed in pypdf==6.16.1.
If you cannot upgrade yet, consider applying the changes from PR #3966.
{
"nvd_published_at": null,
"github_reviewed_at": "2026-09-01T21:27:22Z",
"severity": "MODERATE",
"github_reviewed": true,
"cwe_ids": [
"CWE-834"
]
}