An attacker who uses this vulnerability can craft a PDF which leads to long runtimes. This requires a call to read_until_whitespace with an input which does not have whitespace for a long time.
This has been fixed in pypdf==6.15.0.
If you cannot upgrade yet, consider applying the changes from PR #3947.
{
"cwe_ids": [
"CWE-407"
],
"github_reviewed": true,
"github_reviewed_at": "2026-09-02T14:38:12Z",
"nvd_published_at": "2026-08-31T22:17:23Z",
"severity": "MODERATE"
}