{"id":"CVE-2019-16791","aliases":["GHSA-h92m-42h4-82f6","PYSEC-2020-174"],"url":"https://o3.security/vulnerability/CVE-2019-16791","summary":"postfix-mta-sts-resolver Algorithm Downgrade vulnerability","details":"In postfix-mta-sts-resolver before 0.5.1, All users can receive incorrect response from daemon under rare conditions, rendering downgrade of effective STS policy.","published":"2020-01-22T02:15:11.367Z","modified":"2026-07-09T02:48:50.499585Z","cvss":{"score":5.9,"severity":"MEDIUM","vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H"},"epss":null,"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"PyPI","name":"postfix-mta-sts-resolver","fixedVersion":"0.5.1"}],"fix":null,"references":[{"type":"FIX","url":"https://gist.github.com/Snawoot/b9da85d6b26dea5460673b29df1adc6b"},{"type":"FIX","url":"https://github.com/Snawoot/postfix-mta-sts-resolver/security/advisories/GHSA-h92m-42h4-82f6"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-07-09T02:48:50.499585Z"}}