An attacker who uses this vulnerability can craft a PDF which leads to long runtimes. This requires accessing a stream which uses the /ASCIIHexDecode filter.
This has been fixed in pypdf==6.7.5.
If you cannot upgrade yet, consider applying the changes from PR #3666.
{
"cwe_ids": [
"CWE-407"
],
"github_reviewed_at": "2026-03-02T22:03:45Z",
"nvd_published_at": "2026-03-06T07:16:01Z",
"github_reviewed": true,
"severity": "MODERATE"
}