{"cve":"CVE-2023-36807","nvd":{"published":"2023-06-30T19:15:09.283","modified":"2026-06-17T06:07:07.070","status":"Modified","description":"pypdf is a pure-python PDF library capable of splitting, merging, cropping, and transforming the pages of PDF files. In version 2.10.5 an attacker who uses this vulnerability 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 if the user extracted metadata from such a malformed PDF. Versions prior to 2.10.5 throw an error, but do not hang forever. This issue was fixed with https://github.com/py-pdf/pypdf/pull/1331 which has been included in release 2.10.6. Users are advised to upgrade. Users unable to upgrade should modify `PyPDF2/generic/_data_structures.py::read_object` to an an error throwing case. See GHSA-hm9v-vj3r-r55m for details.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H","score":6.5},"cwes":["CWE-835"],"references":["https://github.com/py-pdf/pypdf/issues/1329","https://github.com/py-pdf/pypdf/pull/1331","https://github.com/py-pdf/pypdf/security/advisories/GHSA-hm9v-vj3r-r55m","https://github.com/py-pdf/pypdf/issues/1329","https://github.com/py-pdf/pypdf/pull/1331"],"products":["pypdf_project:pypdf"],"source":"nvd","synced_at":"2026-10-19T21:38:30.124994567+00:00"},"epss":{"cve":"CVE-2023-36807","score":0.00573,"percentile":0.47369,"date":"2026-11-01"},"kev":null,"osv":[{"id":"GHSA-hm9v-vj3r-r55m","url":"https://osv.dev/vulnerability/GHSA-hm9v-vj3r-r55m","summary":"PyPDF2 vulnerable to possible Infinite Loop when reading malformed objects","modified":"2026-07-07T17:56:23.416854613Z","packages":[{"ecosystem":"PyPI","name":"pypdf2","purl":"pkg:pypi/pypdf2","ranges":[">=2.10.5 <2.10.6"],"fixed":["2.10.6"]}]},{"id":"PYSEC-2026-1836","url":"https://osv.dev/vulnerability/PYSEC-2026-1836","summary":"PyPDF2 vulnerable to possible Infinite Loop when reading malformed objects","modified":"2026-07-07T17:46:59.504076185Z","packages":[{"ecosystem":"PyPI","name":"pypdf2","purl":"pkg:pypi/pypdf2","ranges":[">=2.10.5 <2.10.6"],"fixed":["2.10.6"]}]}],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}