{"id":"CVE-2026-71870","aliases":["GHSA-fp3f-mc75-235c","PYSEC-2026-3655"],"url":"https://o3.security/vulnerability/CVE-2026-71870","summary":"pypdf: Possible large memory usage for large /ToUnicode streams","details":"### Impact\n\nAn attacker who uses this vulnerability can craft a PDF which leads to large memory consumption. This requires parsing the `/ToUnicode` entry of a font with unusually large values, for example during text extraction.\n\n### Patches\n\nThis has been fixed in [pypdf==6.15.0](https://github.com/py-pdf/pypdf/releases/tag/6.15.0).\n\n### Workarounds\n\nIf you cannot upgrade yet, consider applying the changes from PR [#3944](https://github.com/py-pdf/pypdf/pull/3944).","published":"2026-08-07T19:28:26.178Z","modified":"2026-09-11T03:48:41.685367520Z","cvss":null,"epss":{"score":0.00127,"percentile":0.02567,"asOf":"2026-08-24"},"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"PyPI","name":"pypdf","fixedVersion":"6.15.0"}],"fix":{"url":"https://github.com/py-pdf/pypdf/commit/afba8080e19d29a3c256a742b340995e695b35aa","label":"py-pdf/pypdf@afba808"},"references":[{"type":"WEB","url":"https://github.com/py-pdf/pypdf/releases/tag/6.15.0"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/71xxx/CVE-2026-71870.json"},{"type":"ADVISORY","url":"https://github.com/py-pdf/pypdf/security/advisories/GHSA-fp3f-mc75-235c"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-71870"},{"type":"FIX","url":"https://github.com/py-pdf/pypdf/commit/afba8080e19d29a3c256a742b340995e695b35aa"},{"type":"FIX","url":"https://github.com/py-pdf/pypdf/pull/3944"},{"type":"PACKAGE","url":"https://github.com/py-pdf/pypdf"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-09-11T03:48:41.685367520Z"}}