{"id":"CVE-2026-22691","summary":"pypdf has possible long runtimes for malformed startxref","details":"pypdf is a free and open-source pure-python PDF library. Prior to version 6.6.0, pypdf has possible long runtimes for malformed startxref. An attacker who uses this vulnerability can craft a PDF which leads to possibly long runtimes for invalid startxref entries. When rebuilding the cross-reference table, PDF files with lots of whitespace characters become problematic. Only the non-strict reading mode is affected. Only the non-strict reading mode is affected. This issue has been patched in version 6.6.0.","aliases":["GHSA-4f6g-68pf-7vhv"],"modified":"2026-04-10T05:38:49.727592Z","published":"2026-01-10T04:46:12.423Z","database_specific":{"cwe_ids":["CWE-1333","CWE-400"],"cna_assigner":"GitHub_M","osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/22xxx/CVE-2026-22691.json"},"references":[{"type":"WEB","url":"https://github.com/py-pdf/pypdf/releases/tag/6.6.0"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/22xxx/CVE-2026-22691.json"},{"type":"ADVISORY","url":"https://github.com/py-pdf/pypdf/security/advisories/GHSA-4f6g-68pf-7vhv"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-22691"},{"type":"FIX","url":"https://github.com/py-pdf/pypdf/commit/294165726b646bb7799be1cc787f593f2fdbcf45"},{"type":"FIX","url":"https://github.com/py-pdf/pypdf/pull/3594"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/py-pdf/pypdf","events":[{"introduced":"0"},{"fixed":"10df9c72fa7fb9ab14101b9cb911d66e680282a8"}]}],"versions":["1.26.0","1.27.0","1.27.1","1.27.10","1.27.11","1.27.12","1.27.2","1.27.3","1.27.4","1.27.5","1.27.6","1.27.7","1.27.8","1.27.9","1.28.0","1.28.1","1.28.2","2.0.0","2.1.0","2.1.1","2.10.0","2.10.1","2.10.2","2.10.3","2.10.4","2.10.5","2.10.6","2.10.7","2.10.8","2.10.9","2.11.0","2.11.1","2.11.2","2.12.0","2.12.1","2.2.0","2.2.1","2.3.0","2.3.1","2.4.0","2.4.1","2.4.2","2.5.0","2.6.0","2.7.0","2.8.0","2.8.1","2.9.0","3.0.0","3.1.0","3.10.0","3.11.0","3.11.1","3.12.0","3.12.1","3.12.2","3.13.0","3.14.0","3.15.0","3.15.1","3.15.2","3.15.3","3.15.4","3.15.5","3.16.0","3.16.1","3.16.2","3.16.3","3.16.4","3.17.0","3.17.1","3.17.2","3.17.3","3.17.4","3.2.0","3.2.1","3.3.0","3.4.0","3.4.1","3.5.0","3.5.1","3.5.2","3.6.0","3.7.0","3.7.1","3.8.0","3.8.1","3.9.0","3.9.1","4.0.0","4.0.1","4.0.2","4.1.0","4.2.0","4.3.0","4.3.1","5.0.0","5.0.1","5.1.0","5.2.0","5.3.0","5.3.1","5.4.0","5.5.0","5.6.0","5.6.1","5.7.0","5.8.0","5.9.0","6.0.0","6.1.0","6.1.1","6.1.2","6.1.3","6.2.0","6.3.0","6.4.0","6.4.1","6.4.2","6.5.0","v1.17","v1.18","v1.19","v1.20","v1.21","v1.22","v1.23","v1.24","v1.25","v1.25.1"],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-22691.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V4","score":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:U"}]}