{"id":"CVE-2016-9243","aliases":["GHSA-q3cj-2r34-2cwc","PYSEC-2017-8"],"url":"https://o3.security/vulnerability/CVE-2016-9243","summary":"Improper input validation in cryptography","details":"HKDF in cryptography before 1.5.2 returns an empty byte-string if used with a length less than algorithm.digest_size.","published":"2017-03-27T17:59:00.460Z","modified":"2026-10-20T10:48:00.141328756Z","cvss":{"score":7.5,"severity":"HIGH","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N"},"epss":null,"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"PyPI","name":"cryptography","fixedVersion":"1.5.3"}],"fix":{"url":"https://github.com/pyca/cryptography/commit/b924696b2e8731f39696584d12cceeb3aeb2d874","label":"pyca/cryptography@b924696"},"references":[{"type":"ADVISORY","url":"http://www.securityfocus.com/bid/94216"},{"type":"ADVISORY","url":"http://www.ubuntu.com/usn/USN-3138-1"},{"type":"ADVISORY","url":"https://cryptography.io/en/latest/changelog"},{"type":"ADVISORY","url":"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/5R2ZOBMPWDFFHUZ6QOZZY36A6H5CGJXL/"},{"type":"ADVISORY","url":"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/U23KDR2M2N7W2ZSREG63BVW7D4VC6CIZ/"},{"type":"ADVISORY","url":"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/WQ5G7KHKZC4SI23JE7277KZXM57GEQKT/"},{"type":"REPORT","url":"https://github.com/pyca/cryptography/issues/3211"},{"type":"FIX","url":"http://www.openwall.com/lists/oss-security/2016/11/09/2"},{"type":"FIX","url":"https://github.com/pyca/cryptography/commit/b924696b2e8731f39696584d12cceeb3aeb2d874"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2016-9243"},{"type":"WEB","url":"https://cryptography.io/en/latest/changelog/#v1-5-3"},{"type":"ADVISORY","url":"https://github.com/advisories/GHSA-q3cj-2r34-2cwc"},{"type":"PACKAGE","url":"https://github.com/pyca/cryptography"},{"type":"WEB","url":"https://github.com/pypa/advisory-database/tree/main/vulns/cryptography/PYSEC-2017-8.yaml"},{"type":"WEB","url":"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/5R2ZOBMPWDFFHUZ6QOZZY36A6H5CGJXL"},{"type":"WEB","url":"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/U23KDR2M2N7W2ZSREG63BVW7D4VC6CIZ"},{"type":"WEB","url":"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/WQ5G7KHKZC4SI23JE7277KZXM57GEQKT"},{"type":"WEB","url":"https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/5R2ZOBMPWDFFHUZ6QOZZY36A6H5CGJXL"},{"type":"WEB","url":"https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/U23KDR2M2N7W2ZSREG63BVW7D4VC6CIZ"},{"type":"WEB","url":"https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/WQ5G7KHKZC4SI23JE7277KZXM57GEQKT"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-10-20T10:48:00.141328756Z"}}