{"id":"CVE-2023-46250","aliases":["GHSA-wjcc-cq79-p63f","PYSEC-2026-1834"],"url":"https://o3.security/vulnerability/CVE-2023-46250","summary":"pypdf possible Infinite Loop when PdfWriter(clone_from) is used with a PDF","details":"pypdf is a free and open-source pure-python PDF library. An attacker who uses a vulnerability present in versions 3.7.0 through 3.16.4 can craft a PDF which leads to an infinite loop. This infinite loop blocks the current process and can utilize a single core of the CPU by 100%. It does not affect memory usage. That is, for example, the case when the pypdf-user manipulates an incoming malicious PDF e.g. by merging it with another PDF or by adding annotations. The issue was fixed in version 3.17.0. As a workaround, apply the patch manually by modifying `pypdf/generic/_data_structures.py`.","published":"2023-10-31T15:23:32.852Z","modified":"2026-07-15T01:49:15.265677287Z","cvss":{"score":5.1,"severity":"MEDIUM","vector":"CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H"},"epss":null,"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"PyPI","name":"pypdf","fixedVersion":"3.17.0"}],"fix":{"url":"https://github.com/py-pdf/pypdf/commit/9b23ac3c9619492570011d551d521690de9a3e2d","label":"py-pdf/pypdf@9b23ac3"},"references":[{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2023/46xxx/CVE-2023-46250.json"},{"type":"ADVISORY","url":"https://github.com/py-pdf/pypdf/security/advisories/GHSA-wjcc-cq79-p63f"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2023-46250"},{"type":"FIX","url":"https://github.com/py-pdf/pypdf/commit/9b23ac3c9619492570011d551d521690de9a3e2d"},{"type":"FIX","url":"https://github.com/py-pdf/pypdf/pull/2264"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-07-15T01:49:15.265677287Z"}}