{"id":"CVE-2016-6580","aliases":["GHSA-h3q4-6j7f-r24c","PYSEC-2017-93"],"url":"https://o3.security/vulnerability/CVE-2016-6580","summary":"priority vulnerable to denial of service","details":"A HTTP/2 implementation built using any version of the Python priority library prior to version 1.2.0 could be targeted by a malicious peer by having that peer assign priority information for every possible HTTP/2 stream ID. The priority tree would happily continue to store the priority information for each stream, and would therefore allocate unbounded amounts of memory. Attempting to actually use a tree like this would also cause extremely high CPU usage to maintain the tree.","published":"2017-01-10T15:59:00.377Z","modified":"2026-10-24T10:30:52.710711405Z","cvss":{"score":7.5,"severity":"HIGH","vector":"CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"},"epss":null,"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"PyPI","name":"priority","fixedVersion":"1.2.0"}],"fix":{"url":"https://github.com/python-hyper/priority/commit/7d01a7dc4db83bce50f20d47caf4f37b403a3ecd","label":"python-hyper/priority@7d01a7d"},"references":[{"type":"ADVISORY","url":"http://www.securityfocus.com/bid/92311"},{"type":"ADVISORY","url":"https://python-hyper.org/priority/en/latest/security/CVE-2016-6580.html"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2016-6580"},{"type":"WEB","url":"https://github.com/python-hyper/priority/commit/7d01a7dc4db83bce50f20d47caf4f37b403a3ecd"},{"type":"WEB","url":"https://github.com/pypa/advisory-database/tree/main/vulns/priority/PYSEC-2017-93.yaml"},{"type":"PACKAGE","url":"https://github.com/python-hyper/priority"},{"type":"WEB","url":"https://web.archive.org/web/20160806004329/http://www.securityfocus.com/bid/92311"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-10-24T10:30:52.710711405Z"}}