An attacker who uses this vulnerability can craft a PDF which leads to arbitrary image parsers being called. This requires loading an image which claims to use the /DCTDecode filter (JPEG data).
Users which do not have the optional Pillow dependency installed in their environment are not affected.
This has been fixed in pypdf==6.21.1.
If you cannot upgrade yet, consider applying the changes from PR #4222.
{
"cwe_ids": [
"CWE-183",
"CWE-20"
],
"github_reviewed": true,
"github_reviewed_at": "2026-10-21T19:58:10Z",
"nvd_published_at": "2026-10-21T15:17:16Z",
"severity": "LOW"
}