{"id":"CVE-2019-9515","url":"https://www.cyber-defence.io/tools/cve/CVE-2019-9515","generatedAt":"2026-10-27T23:37:54.481Z","title":"Some HTTP/2 implementations are vulnerable to a settings flood, potentially leading to a denial of service.","description":"Some HTTP/2 implementations are vulnerable to a settings flood, potentially leading to a denial of service. The attacker sends a stream of SETTINGS frames to the peer. Since the RFC requires that the peer reply with one acknowledgement per SETTINGS frame, an empty SETTINGS frame is almost equivalent in behavior to a ping. Depending on how efficiently this data is queued, this can consume excess CPU, memory, or both.","published":"2019-08-13T21:15:13.000Z","lastModified":"2026-06-17T02:43:53.000Z","status":"Modified","sourceIdentifier":"cret@cert.org","cvss":{"version":"3.1","score":7.5,"severity":"HIGH","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"},"cwe":["CWE-400","CWE-770"],"affected":["apple/swiftnio","apache/traffic server","canonical/ubuntu linux","debian/debian linux","synology/skynas","synology/diskstation manager","synology/vs960hd firmware","fedoraproject/fedora","opensuse/leap","redhat/jboss core services","redhat/jboss enterprise application platform","redhat/openshift container platform","redhat/openshift service mesh","redhat/openstack","redhat/quay","redhat/single sign-on","redhat/software collections","redhat/enterprise linux","oracle/graalvm","mcafee/web gateway","f5/big-ip local traffic manager","nodejs/node.js"],"epss":{"score":0.87286,"percentile":0.9975,"date":"2026-10-26","history":[]},"kev":{"listed":false},"exploits":{"count":0,"verified":false,"firstPublished":null,"source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[]},"verdict":{"level":"urgent","text":"EPSS puts the probability of exploitation in the next 30 days at 87.3%, higher than 100% of all known CVEs. Patch or mitigate before the next change window."},"changes":[],"references":[{"url":"http://lists.opensuse.org/opensuse-security-announce/2019-09/msg00031.html","tags":["Mailing List","Third Party Advisory"],"source":"cret@cert.org"},{"url":"http://lists.opensuse.org/opensuse-security-announce/2019-09/msg00032.html","tags":["Mailing List","Third Party Advisory"],"source":"cret@cert.org"},{"url":"http://seclists.org/fulldisclosure/2019/Aug/16","tags":["Mailing List","Third Party Advisory"],"source":"cret@cert.org"},{"url":"https://access.redhat.com/errata/RHSA-2019:2766","tags":["Third Party Advisory"],"source":"cret@cert.org"},{"url":"https://access.redhat.com/errata/RHSA-2019:2796","tags":["Third Party Advisory"],"source":"cret@cert.org"},{"url":"https://access.redhat.com/errata/RHSA-2019:2861","tags":["Third Party Advisory"],"source":"cret@cert.org"},{"url":"https://access.redhat.com/errata/RHSA-2019:2925","tags":["Third Party Advisory"],"source":"cret@cert.org"},{"url":"https://access.redhat.com/errata/RHSA-2019:2939","tags":["Third Party Advisory"],"source":"cret@cert.org"},{"url":"https://access.redhat.com/errata/RHSA-2019:2955","tags":["Third Party Advisory"],"source":"cret@cert.org"},{"url":"https://access.redhat.com/errata/RHSA-2019:3892","tags":["Third Party Advisory"],"source":"cret@cert.org"},{"url":"https://access.redhat.com/errata/RHSA-2019:4018","tags":["Third Party Advisory"],"source":"cret@cert.org"},{"url":"https://access.redhat.com/errata/RHSA-2019:4019","tags":["Third Party Advisory"],"source":"cret@cert.org"},{"url":"https://access.redhat.com/errata/RHSA-2019:4020","tags":["Third Party Advisory"],"source":"cret@cert.org"},{"url":"https://access.redhat.com/errata/RHSA-2019:4021","tags":["Third Party Advisory"],"source":"cret@cert.org"},{"url":"https://access.redhat.com/errata/RHSA-2019:4040","tags":["Third Party Advisory"],"source":"cret@cert.org"},{"url":"https://access.redhat.com/errata/RHSA-2019:4041","tags":["Third Party Advisory"],"source":"cret@cert.org"},{"url":"https://access.redhat.com/errata/RHSA-2019:4042","tags":["Third Party Advisory"],"source":"cret@cert.org"},{"url":"https://access.redhat.com/errata/RHSA-2019:4045","tags":["Third Party Advisory"],"source":"cret@cert.org"},{"url":"https://access.redhat.com/errata/RHSA-2019:4352","tags":["Third Party Advisory"],"source":"cret@cert.org"},{"url":"https://access.redhat.com/errata/RHSA-2020:0727","tags":["Third Party Advisory"],"source":"cret@cert.org"},{"url":"https://github.com/Netflix/security-bulletins/blob/master/advisories/third-party/2019-002.md","tags":["Third Party Advisory"],"source":"cret@cert.org"},{"url":"https://kb.cert.org/vuls/id/605641/","tags":["Third Party Advisory","US Government Resource"],"source":"cret@cert.org"},{"url":"https://kc.mcafee.com/corporate/index?page=content&id=SB10296","tags":["Third Party Advisory"],"source":"cret@cert.org"},{"url":"https://lists.apache.org/thread.html/392108390cef48af647a2e47b7fd5380e050e35ae8d1aa2030254c04%40%3Cusers.trafficserver.apache.org%3E","source":"cret@cert.org"},{"url":"https://lists.apache.org/thread.html/ad3d01e767199c1aed8033bb6b3f5bf98c011c7c536f07a5d34b3c19%40%3Cannounce.trafficserver.apache.org%3E","source":"cret@cert.org"},{"url":"https://lists.apache.org/thread.html/bde52309316ae798186d783a5e29f4ad1527f61c9219a289d0eee0a7%40%3Cdev.trafficserver.apache.org%3E","source":"cret@cert.org"},{"url":"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/4ZQGHE3WTYLYAYJEIDJVF2FIGQTAYPMC/","source":"cret@cert.org"},{"url":"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/CMNFX5MNYRWWIMO4BTKYQCGUDMHO3AXP/","source":"cret@cert.org"},{"url":"https://seclists.org/bugtraq/2019/Aug/24","tags":["Mailing List","Third Party Advisory"],"source":"cret@cert.org"},{"url":"https://seclists.org/bugtraq/2019/Aug/43","tags":["Mailing List","Third Party Advisory"],"source":"cret@cert.org"},{"url":"https://seclists.org/bugtraq/2019/Sep/18","tags":["Mailing List","Third Party Advisory"],"source":"cret@cert.org"},{"url":"https://security.netapp.com/advisory/ntap-20190823-0005/","tags":["Third Party Advisory"],"source":"cret@cert.org"},{"url":"https://support.f5.com/csp/article/K50233772","tags":["Third Party Advisory"],"source":"cret@cert.org"},{"url":"https://support.f5.com/csp/article/K50233772?utm_source=f5support&amp%3Butm_medium=RSS","source":"cret@cert.org"},{"url":"https://usn.ubuntu.com/4308-1/","tags":["Third Party Advisory"],"source":"cret@cert.org"},{"url":"https://www.debian.org/security/2019/dsa-4508","tags":["Third Party Advisory"],"source":"cret@cert.org"},{"url":"https://www.debian.org/security/2019/dsa-4520","tags":["Third Party Advisory"],"source":"cret@cert.org"},{"url":"https://www.synology.com/security/advisory/Synology_SA_19_33","tags":["Third Party Advisory"],"source":"cret@cert.org"},{"url":"http://lists.opensuse.org/opensuse-security-announce/2019-09/msg00031.html","tags":["Mailing List","Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"http://lists.opensuse.org/opensuse-security-announce/2019-09/msg00032.html","tags":["Mailing List","Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"http://seclists.org/fulldisclosure/2019/Aug/16","tags":["Mailing List","Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://access.redhat.com/errata/RHSA-2019:2766","tags":["Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://access.redhat.com/errata/RHSA-2019:2796","tags":["Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://access.redhat.com/errata/RHSA-2019:2861","tags":["Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://access.redhat.com/errata/RHSA-2019:2925","tags":["Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://access.redhat.com/errata/RHSA-2019:2939","tags":["Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://access.redhat.com/errata/RHSA-2019:2955","tags":["Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://access.redhat.com/errata/RHSA-2019:3892","tags":["Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://access.redhat.com/errata/RHSA-2019:4018","tags":["Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://access.redhat.com/errata/RHSA-2019:4019","tags":["Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://access.redhat.com/errata/RHSA-2019:4020","tags":["Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://access.redhat.com/errata/RHSA-2019:4021","tags":["Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://access.redhat.com/errata/RHSA-2019:4040","tags":["Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://access.redhat.com/errata/RHSA-2019:4041","tags":["Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://access.redhat.com/errata/RHSA-2019:4042","tags":["Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://access.redhat.com/errata/RHSA-2019:4045","tags":["Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://access.redhat.com/errata/RHSA-2019:4352","tags":["Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://access.redhat.com/errata/RHSA-2020:0727","tags":["Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://github.com/Netflix/security-bulletins/blob/master/advisories/third-party/2019-002.md","tags":["Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://kb.cert.org/vuls/id/605641/","tags":["Third Party Advisory","US Government Resource"],"source":"af854a3a-2127-422b-91ae-364da2661108"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2019-9515","epss":"https://www.first.org/epss/","kev":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","exploitdb":"https://www.exploit-db.com/"},"licence":"CC BY 4.0 — link back to the CVE Explorer if you publish the results; upstream data remains subject to its own terms."}