{"id":"CVE-2020-35917","aliases":["GHSA-2vx6-fcw6-hpr6","RUSTSEC-2020-0074"],"url":"https://o3.security/vulnerability/CVE-2020-35917","summary":"Reference counting error in pyo3","details":"An issue was discovered in the pyo3 crate before 0.12.4 for Rust. There is a reference-counting error and use-after-free in From<Py<T>>.","published":"2020-12-31T09:15:15.833Z","modified":"2026-09-15T14:15:08.294070Z","cvss":{"score":5.5,"severity":"MEDIUM","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H"},"epss":null,"cisaKev":null,"exploitsKnown":1,"affectedPackages":[{"ecosystem":"crates.io","name":"pyo3","fixedVersion":"0.12.4"}],"fix":{"url":"https://github.com/PyO3/pyo3/pull/1297","label":"PyO3/pyo3#1297"},"references":[{"type":"FIX","url":"https://rustsec.org/advisories/RUSTSEC-2020-0074.html"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2020-35917"},{"type":"WEB","url":"https://github.com/PyO3/pyo3/pull/1297"},{"type":"WEB","url":"https://github.com/PyO3/pyo3/commit/8f81f595dd770b586c7ca7195b42004a6c976eb9"},{"type":"PACKAGE","url":"https://github.com/PyO3/pyo3"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-09-15T14:15:08.294070Z"}}