{"id":"CVE-2026-82398","aliases":["GHSA-fc8x-2rww-xw9m"],"url":"https://o3.security/vulnerability/CVE-2026-82398","summary":"pypdf: Inefficient handling of non-whitespace inputs in read_until_whitespace","details":"pypdf is a free and open-source pure-python PDF library. Prior to 6.15.0, an attacker can craft a PDF that causes long runtimes when the pypdf/_utils.py function read_until_whitespace reads a stream containing a long run of bytes without whitespace. The function repeatedly performs immutable bytes concatenation in a one-byte loop, causing quadratic processing cost for the long non-whitespace input. This issue is fixed in version 6.15.0.","published":"2026-08-31T21:41:10.272Z","modified":"2026-09-03T03:30:50.415673764Z","cvss":null,"epss":{"score":0.00301,"percentile":0.22322,"asOf":"2026-09-02"},"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"PyPI","name":"pypdf","fixedVersion":"6.15.0"}],"fix":{"url":"https://github.com/py-pdf/pypdf/commit/4959848e057e37c218dccad7465259210923faaa","label":"py-pdf/pypdf@4959848"},"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/2026/82xxx/CVE-2026-82398.json"},{"type":"ADVISORY","url":"https://github.com/py-pdf/pypdf/security/advisories/GHSA-fc8x-2rww-xw9m"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-82398"},{"type":"FIX","url":"https://github.com/py-pdf/pypdf/commit/4959848e057e37c218dccad7465259210923faaa"},{"type":"FIX","url":"https://github.com/py-pdf/pypdf/pull/3947"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-09-03T03:30:50.415673764Z"}}