An attacker who uses this vulnerability can craft a PDF which leads to the RAM being exhausted. This requires accessing a stream compressed using /FlateDecode with a /Predictor unequal 1 and large predictor parameters.
This has been fixed in pypdf==6.10.2.
If you cannot upgrade yet, consider applying the changes from PR #3734.
{
"severity": "MODERATE",
"github_reviewed": true,
"nvd_published_at": null,
"cwe_ids": [
"CWE-789"
],
"github_reviewed_at": "2026-04-16T21:30:00Z"
}