{"schemaVersion":3,"id":"CVE-2016-6580","aliases":["GHSA-h3q4-6j7f-r24c","PYSEC-2017-93"],"status":"published","duplicateOf":null,"title":null,"description":"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.","dates":{"published":"2017-01-10T15:00:00.000Z","modified":"2024-08-06T01:36:28.170Z","reserved":null,"kevAdded":[],"kevDue":[]},"cvss":{"headline":{"score":7.5,"severity":"high","version":"3.0","versionLabel":"v3.0","source":"NVD","vector":"CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","computed":false,"selection":"backend-summary"},"metrics":[{"version":"3.0","versionLabel":"v3.0","source":"NVD","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","exploitability":null,"impact":null,"computed":false},{"version":"2.0","versionLabel":"v2.0","source":"NVD","score":5,"severity":"medium","vector":"AV:N/AC:L/Au:N/C:N/I:N/A:P","exploitability":null,"impact":null,"computed":false},{"version":"4.0","versionLabel":"v4.0","source":"OSV · Pypi","score":8.7,"severity":"high","vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U","exploitability":null,"impact":null,"computed":true},{"version":"3.0","versionLabel":"v3.0","source":"OSV · Pypi","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","exploitability":10,"impact":6,"computed":true}]},"epss":{"probability":0.01807,"percentile":0.78259,"severity":"low","asOf":"2026-10-19T00:00:00.000Z","change":{"pp":0,"baselineDate":"2026-09-19T00:00:00.000Z","baselineScore":0.01807},"history":[{"date":"2026-09-14T00:00:00.000Z","score":0.01807,"percentile":null},{"date":"2026-09-15T00:00:00.000Z","score":0.01807,"percentile":null},{"date":"2026-09-16T00:00:00.000Z","score":0.01807,"percentile":null},{"date":"2026-09-17T00:00:00.000Z","score":0.01807,"percentile":null},{"date":"2026-09-18T00:00:00.000Z","score":0.01807,"percentile":null},{"date":"2026-09-19T00:00:00.000Z","score":0.01807,"percentile":null},{"date":"2026-09-20T00:00:00.000Z","score":0.01807,"percentile":null},{"date":"2026-09-21T00:00:00.000Z","score":0.01684,"percentile":null},{"date":"2026-09-22T00:00:00.000Z","score":0.01807,"percentile":null},{"date":"2026-09-23T00:00:00.000Z","score":0.01807,"percentile":null},{"date":"2026-09-24T00:00:00.000Z","score":0.01807,"percentile":null},{"date":"2026-09-25T00:00:00.000Z","score":0.01807,"percentile":null},{"date":"2026-09-26T00:00:00.000Z","score":0.01807,"percentile":null},{"date":"2026-09-27T00:00:00.000Z","score":0.01807,"percentile":null},{"date":"2026-09-28T00:00:00.000Z","score":0.01807,"percentile":null},{"date":"2026-09-29T00:00:00.000Z","score":0.01807,"percentile":null},{"date":"2026-09-30T00:00:00.000Z","score":0.01807,"percentile":null},{"date":"2026-10-01T00:00:00.000Z","score":0.01807,"percentile":null},{"date":"2026-10-02T00:00:00.000Z","score":0.01807,"percentile":null},{"date":"2026-10-03T00:00:00.000Z","score":0.01807,"percentile":null},{"date":"2026-10-04T00:00:00.000Z","score":0.01807,"percentile":null},{"date":"2026-10-05T00:00:00.000Z","score":0.01807,"percentile":null},{"date":"2026-10-06T00:00:00.000Z","score":0.01807,"percentile":null},{"date":"2026-10-07T00:00:00.000Z","score":0.01807,"percentile":null},{"date":"2026-10-08T00:00:00.000Z","score":0.01807,"percentile":null},{"date":"2026-10-09T00:00:00.000Z","score":0.01807,"percentile":null},{"date":"2026-10-10T00:00:00.000Z","score":0.01807,"percentile":null},{"date":"2026-10-11T00:00:00.000Z","score":0.01807,"percentile":null},{"date":"2026-10-12T00:00:00.000Z","score":0.01807,"percentile":null},{"date":"2026-10-13T00:00:00.000Z","score":0.01807,"percentile":null},{"date":"2026-10-14T00:00:00.000Z","score":0.01807,"percentile":null},{"date":"2026-10-15T00:00:00.000Z","score":0.01807,"percentile":null},{"date":"2026-10-16T00:00:00.000Z","score":0.01807,"percentile":null},{"date":"2026-10-17T00:00:00.000Z","score":0.01807,"percentile":null},{"date":"2026-10-18T00:00:00.000Z","score":0.01807,"percentile":null},{"date":"2026-10-19T00:00:00.000Z","score":0.01807,"percentile":0.78259}],"last30":[{"date":"2026-09-19T00:00:00.000Z","score":0.01807,"percentile":null},{"date":"2026-09-20T00:00:00.000Z","score":0.01807,"percentile":null},{"date":"2026-09-21T00:00:00.000Z","score":0.01684,"percentile":null},{"date":"2026-09-22T00:00:00.000Z","score":0.01807,"percentile":null},{"date":"2026-09-23T00:00:00.000Z","score":0.01807,"percentile":null},{"date":"2026-09-24T00:00:00.000Z","score":0.01807,"percentile":null},{"date":"2026-09-25T00:00:00.000Z","score":0.01807,"percentile":null},{"date":"2026-09-26T00:00:00.000Z","score":0.01807,"percentile":null},{"date":"2026-09-27T00:00:00.000Z","score":0.01807,"percentile":null},{"date":"2026-09-28T00:00:00.000Z","score":0.01807,"percentile":null},{"date":"2026-09-29T00:00:00.000Z","score":0.01807,"percentile":null},{"date":"2026-09-30T00:00:00.000Z","score":0.01807,"percentile":null},{"date":"2026-10-01T00:00:00.000Z","score":0.01807,"percentile":null},{"date":"2026-10-02T00:00:00.000Z","score":0.01807,"percentile":null},{"date":"2026-10-03T00:00:00.000Z","score":0.01807,"percentile":null},{"date":"2026-10-04T00:00:00.000Z","score":0.01807,"percentile":null},{"date":"2026-10-05T00:00:00.000Z","score":0.01807,"percentile":null},{"date":"2026-10-06T00:00:00.000Z","score":0.01807,"percentile":null},{"date":"2026-10-07T00:00:00.000Z","score":0.01807,"percentile":null},{"date":"2026-10-08T00:00:00.000Z","score":0.01807,"percentile":null},{"date":"2026-10-09T00:00:00.000Z","score":0.01807,"percentile":null},{"date":"2026-10-10T00:00:00.000Z","score":0.01807,"percentile":null},{"date":"2026-10-11T00:00:00.000Z","score":0.01807,"percentile":null},{"date":"2026-10-12T00:00:00.000Z","score":0.01807,"percentile":null},{"date":"2026-10-13T00:00:00.000Z","score":0.01807,"percentile":null},{"date":"2026-10-14T00:00:00.000Z","score":0.01807,"percentile":null},{"date":"2026-10-15T00:00:00.000Z","score":0.01807,"percentile":null},{"date":"2026-10-16T00:00:00.000Z","score":0.01807,"percentile":null},{"date":"2026-10-17T00:00:00.000Z","score":0.01807,"percentile":null},{"date":"2026-10-18T00:00:00.000Z","score":0.01807,"percentile":null},{"date":"2026-10-19T00:00:00.000Z","score":0.01807,"percentile":0.78259}]},"kev":{"state":"not-listed","entries":[],"listedCount":0,"totalCatalogs":3,"catalogs":[{"source":"cisa","label":"CISA","listed":false,"entry":null},{"source":"enisa","label":"ENISA","listed":false,"entry":null},{"source":"circl","label":"CIRCL","listed":false,"entry":null}]},"ransomware":{"state":"none-recorded","sources":[]},"exploits":[],"exploitCount":0,"weaknesses":[{"id":"CWE-399","name":"Resource Management Errors","description":"Weaknesses in this category are related to improper management of system resources.","type":"category","status":"Draft","abstraction":null,"likelihoodOfExploit":null,"url":"https://cwe.mitre.org/data/definitions/399.html"}],"affected":[{"vendor":"PyPI","product":"priority","name":"priority","label":"priority","ecosystem":"PyPI","cpePart":null,"purl":"pkg:pypi/priority","purlType":"pypi","versions":[{"text":"< 1.2.0","noFixRecorded":false,"fixedIn":null}],"versionsText":"< 1.2.0","eol":null,"hubHref":null},{"vendor":"python","product":"python_priority_library","name":"python priority library","label":"python_priority_library","ecosystem":null,"cpePart":"a","purl":null,"purlType":null,"versions":[{"text":"1.0.0","noFixRecorded":false,"fixedIn":null},{"text":"1.1.0","noFixRecorded":false,"fixedIn":null},{"text":"1.1.1","noFixRecorded":false,"fixedIn":null}],"versionsText":"1.0.0 | 1.1.0 | 1.1.1","eol":null,"hubHref":"/vendor/python/python_priority_library"}],"affectedCount":2,"eol":{"hasEol":false,"count":0},"references":[{"url":"http://www.securityfocus.com/bid/92311","label":"www.securityfocus.com/bid/92311","hostname":"www.securityfocus.com","tags":["VDB Entry","X Refsource BID","Third Party Advisory","WEB"]},{"url":"https://python-hyper.org/priority/en/latest/security/CVE-2016-6580.html","label":"python-hyper.org/priority/en/latest/security/CVE-2016-6580.html","hostname":"python-hyper.org","tags":["X Refsource CONFIRM","Mitigation","Vendor Advisory","WEB"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2016-6580","label":"nvd.nist.gov/vuln/detail/CVE-2016-6580","hostname":"nvd.nist.gov","tags":["Advisory"]},{"url":"https://github.com/python-hyper/priority/commit/7d01a7dc4db83bce50f20d47caf4f37b403a3ecd","label":"github.com/python-hyper/priority/commit/7d01a7dc4db83bce50f20d47caf4f37b403a3ecd","hostname":"github.com","tags":["WEB"]},{"url":"https://github.com/pypa/advisory-database/tree/main/vulns/priority/PYSEC-2017-93.yaml","label":"github.com/pypa/advisory-database/tree/main/vulns/priority/PYSEC-2017-93.yaml","hostname":"github.com","tags":["WEB"]},{"url":"https://github.com/python-hyper/priority","label":"github.com/python-hyper/priority","hostname":"github.com","tags":["PACKAGE"]},{"url":"https://web.archive.org/web/20160806004329/http://www.securityfocus.com/bid/92311","label":"web.archive.org/web/20160806004329/http://www.securityfocus.com/bid/92311","hostname":"web.archive.org","tags":["WEB"]},{"url":"https://github.com/advisories/GHSA-h3q4-6j7f-r24c","label":"github.com/advisories/GHSA-h3q4-6j7f-r24c","hostname":"github.com","tags":["Advisory"]}],"lineage":{"upstream":[],"downstream":[],"duplicates":[],"related":[]},"timeline":[{"kind":"published","date":"2017-01-10T15:00:00.000Z","label":"Published","detail":"Vulnerability first disclosed.","source":null},{"kind":"modified","date":"2024-08-06T01:36:28.170Z","label":"Last modified","detail":"Vulnerability information updated.","source":null}],"risk":{"score":30,"level":"medium","profile":"Default","thresholds":{"critical":75,"high":50,"medium":25,"low":10}},"meta":{"dataAsOf":"2026-10-19T14:37:14.728Z","stale":false,"partial":false}}