{"id":"CVE-2019-14859","aliases":["GHSA-8qxj-f9rh-9fg2","PYSEC-2020-163"],"url":"https://o3.security/vulnerability/CVE-2019-14859","summary":"Improper Verification of Cryptographic Signature in Pure-Python ECDSA","details":"A flaw was found in all python-ecdsa versions before 0.13.3, where it did not correctly verify whether signatures used DER encoding. Without this verification, a malformed signature could be accepted, making the signature malleable. Without proper verification, an attacker could use a malleable signature to create false transactions.","published":"2020-01-02T15:15:11.960Z","modified":"2026-10-20T10:50:43.819384175Z","cvss":{"score":9.1,"severity":"CRITICAL","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N"},"epss":null,"cisaKev":null,"exploitsKnown":2,"affectedPackages":[{"ecosystem":"PyPI","name":"ecdsa","fixedVersion":"0.13.3"}],"fix":{"url":"https://github.com/warner/python-ecdsa/pull/115","label":"warner/python-ecdsa#115"},"references":[{"type":"ADVISORY","url":"https://github.com/warner/python-ecdsa/releases/tag/python-ecdsa-0.13.3"},{"type":"ADVISORY","url":"https://pypi.org/project/ecdsa/0.13.3/"},{"type":"FIX","url":"https://bugzilla.redhat.com/show_bug.cgi?id=CVE-2019-14859"},{"type":"EVIDENCE","url":"https://github.com/warner/python-ecdsa/issues/114"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2019-14859"},{"type":"WEB","url":"https://github.com/warner/python-ecdsa/pull/115"},{"type":"WEB","url":"https://github.com/tlsfuzzer/python-ecdsa/commit/3427fa29f319b27898a28601955807abb44c0830"},{"type":"WEB","url":"https://github.com/tlsfuzzer/python-ecdsa/commit/9080d1d5ac533da0de00466aaffb49bee808bb4e"},{"type":"WEB","url":"https://github.com/tlsfuzzer/python-ecdsa/commit/b0ea52bb3aa9a16c9a4a91fdc0041edbfed10b31"},{"type":"ADVISORY","url":"https://github.com/advisories/GHSA-8qxj-f9rh-9fg2"},{"type":"WEB","url":"https://github.com/pypa/advisory-database/tree/main/vulns/ecdsa/PYSEC-2020-163.yaml"},{"type":"PACKAGE","url":"https://github.com/warner/python-ecdsa"},{"type":"WEB","url":"https://pypi.org/project/ecdsa/0.13.3"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-10-20T10:50:43.819384175Z"}}