{"cve":"CVE-2023-36810","nvd":{"published":"2023-06-30T19:15:09.357","modified":"2026-06-17T06:07:07.467","status":"Modified","description":"pypdf is a pure-python PDF library capable of splitting, merging, cropping, and transforming the pages of PDF files. An attacker who uses this vulnerability can craft a PDF which leads to unexpected long runtime. This quadratic runtime blocks the current process and can utilize a single core of the CPU by 100%. It does not affect memory usage. This issue has been addressed in PR 808 and versions from 1.27.9 include this fix. Users are advised to upgrade. There are no known workarounds for this vulnerability.","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-407"],"references":["https://github.com/py-pdf/pypdf/issues/582","https://github.com/py-pdf/pypdf/pull/808","https://github.com/py-pdf/pypdf/security/advisories/GHSA-jrm6-h9cq-8gqw","https://lists.debian.org/debian-lts-announce/2023/07/msg00019.html","https://github.com/py-pdf/pypdf/issues/582"],"products":["pypdf_project:pypdf"],"source":"nvd","synced_at":"2026-10-19T21:38:30.124994567+00:00"},"epss":{"cve":"CVE-2023-36810","score":0.0063,"percentile":0.50222,"date":"2026-10-31"},"kev":null,"osv":[{"id":"GHSA-jrm6-h9cq-8gqw","url":"https://osv.dev/vulnerability/GHSA-jrm6-h9cq-8gqw","summary":"PyPDF2 quadratic runtime with malformed PDF missing xref marker","modified":"2026-07-07T17:57:15.295956748Z","packages":[{"ecosystem":"PyPI","name":"pypdf2","purl":"pkg:pypi/pypdf2","ranges":["<1.27.9"],"fixed":["1.27.9"]}]},{"id":"PYSEC-2026-1837","url":"https://osv.dev/vulnerability/PYSEC-2026-1837","summary":"PyPDF2 quadratic runtime with malformed PDF missing xref marker","modified":"2026-07-07T17:46:59.524042100Z","packages":[{"ecosystem":"PyPI","name":"pypdf2","purl":"pkg:pypi/pypdf2","ranges":["<1.27.9"],"fixed":["1.27.9"]}]}],"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."]}