{"id":"CVE-2020-36242","aliases":["GHSA-rhm9-p9w5-fwm7","PYSEC-2021-63"],"url":"https://o3.security/vulnerability/CVE-2020-36242","summary":"PyCA Cryptography symmetrically encrypting large values can lead to integer overflow","details":"In the cryptography package before 3.3.2 for Python, certain sequences of update calls to symmetrically encrypt multi-GB values could result in an integer overflow and buffer overflow, as demonstrated by the Fernet class.","published":"2021-02-07T20:15:12.090Z","modified":"2026-08-07T10:12:00.024016348Z","cvss":{"score":9.1,"severity":"CRITICAL","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H"},"epss":null,"cisaKev":null,"exploitsKnown":null,"affectedPackages":[{"ecosystem":"PyPI","name":"cryptography","fixedVersion":"3.3.2"}],"fix":null,"references":[{"type":"WEB","url":"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/L7RGQLK4J5ZQFRLKCHVVG6BKZTUQMG7E/"},{"type":"ADVISORY","url":"https://github.com/pyca/cryptography/blob/master/CHANGELOG.rst"},{"type":"FIX","url":"https://github.com/pyca/cryptography/compare/3.3.1...3.3.2"},{"type":"FIX","url":"https://github.com/pyca/cryptography/issues/5615"},{"type":"FIX","url":"https://www.oracle.com/security-alerts/cpuapr2022.html"},{"type":"FIX","url":"https://www.oracle.com/security-alerts/cpujul2022.html"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-08-07T10:12:00.024016348Z"}}