An attacker who uses this vulnerability can craft a PDF which leads to long runtimes and large memory consumption. This requires parsing the /ToUnicode entry of a font with unusually large values, for example during text extraction.
This has been fixed in pypdf==6.7.1.
If you cannot upgrade yet, consider applying the changes from PR #3646.
{
"cwe_ids": [
"CWE-834"
],
"github_reviewed": true,
"github_reviewed_at": "2026-02-18T22:41:13Z",
"nvd_published_at": "2026-02-20T22:16:28Z",
"severity": "MODERATE"
}