{"id":"CVE-2026-33123","aliases":["GHSA-qpxp-75px-xjcp","PYSEC-2026-3023"],"url":"https://o3.security/vulnerability/CVE-2026-33123","summary":"pypdf has inefficient decoding of array-based streams","details":"### Impact\nAn attacker who uses this vulnerability can craft a PDF which leads to long runtimes and/or large memory usage. This requires accessing an array-based stream with lots of entries.\n\n### Patches\nThis has been fixed in [pypdf==6.9.1](https://github.com/py-pdf/pypdf/releases/tag/6.9.1).\n\n### Workarounds\nIf you cannot upgrade yet, consider applying the changes from PR [#3686](https://github.com/py-pdf/pypdf/pull/3686).","published":"2026-03-20T09:09:12.831Z","modified":"2026-08-27T14:10:51.932611410Z","cvss":null,"epss":{"score":0.00349,"percentile":0.27538,"asOf":"2026-08-25"},"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"PyPI","name":"pypdf","fixedVersion":"6.9.1"}],"fix":{"url":"https://github.com/py-pdf/pypdf/pull/3686","label":"py-pdf/pypdf#3686"},"references":[{"type":"WEB","url":"https://github.com/py-pdf/pypdf/releases/tag/6.9.1"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/33xxx/CVE-2026-33123.json"},{"type":"ADVISORY","url":"https://github.com/py-pdf/pypdf/security/advisories/GHSA-qpxp-75px-xjcp"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-33123"},{"type":"FIX","url":"https://github.com/py-pdf/pypdf/pull/3686"},{"type":"PACKAGE","url":"https://github.com/py-pdf/pypdf"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-08-27T14:10:51.932611410Z"}}