{"cve":"CVE-2016-6580","nvd":{"published":"2017-01-10T15:59:00.377","modified":"2026-06-17T00:51:24.140","status":"Modified","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.","cvss_v4":null,"cvss_v3":{"version":"3.0","vector":"CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","score":7.5},"cwes":["CWE-399"],"references":["http://www.securityfocus.com/bid/92311","https://python-hyper.org/priority/en/latest/security/CVE-2016-6580.html","http://www.securityfocus.com/bid/92311","https://python-hyper.org/priority/en/latest/security/CVE-2016-6580.html"],"products":["python:python_priority_library"],"source":"nvd","synced_at":"2026-10-19T20:41:25.729257544+00:00"},"epss":{"cve":"CVE-2016-6580","score":0.01807,"percentile":0.78581,"date":"2026-10-31"},"kev":null,"osv":[{"id":"GHSA-h3q4-6j7f-r24c","url":"https://osv.dev/vulnerability/GHSA-h3q4-6j7f-r24c","summary":"priority vulnerable to denial of service","modified":"2024-08-30T23:58:07.907253Z","packages":[{"ecosystem":"PyPI","name":"priority","purl":"pkg:pypi/priority","ranges":["<1.2.0"],"fixed":["1.2.0"]}]},{"id":"PYSEC-2017-93","url":"https://osv.dev/vulnerability/PYSEC-2017-93","summary":"","modified":"2026-06-10T17:01:38.249933537Z","packages":[{"ecosystem":"PyPI","name":"priority","purl":"pkg:pypi/priority","ranges":["<1.2.0"],"fixed":["1.2.0"]}]}],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}