{"id":"CVE-2019-9518","url":"https://www.cyber-defence.io/tools/cve/CVE-2019-9518","generatedAt":"2026-10-27T22:23:46.946Z","title":"Some HTTP/2 implementations are vulnerable to a flood of empty frames, potentially leading to a denial of service.","description":"Some HTTP/2 implementations are vulnerable to a flood of empty frames, potentially leading to a denial of service. The attacker sends a stream of frames with an empty payload and without the end-of-stream flag. These frames can be DATA, HEADERS, CONTINUATION and/or PUSH_PROMISE. The peer spends time processing each frame disproportionate to attack bandwidth. This can consume excess CPU.","published":"2019-08-13T21:15:13.000Z","lastModified":"2026-06-17T02:43:54.000Z","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 service mesh","redhat/quay","redhat/software collections","redhat/enterprise linux","oracle/graalvm","mcafee/web gateway","nodejs/node.js"],"epss":{"score":0.25448,"percentile":0.97935,"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 25.4%, higher than 98% 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-2019:2925","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-2019:4352","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 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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/K46011592","tags":["Third Party Advisory"],"source":"cret@cert.org"},{"url":"https://support.f5.com/csp/article/K46011592?utm_source=f5support&amp%3Butm_medium=RSS","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 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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"},{"url":"https://kc.mcafee.com/corporate/index?page=content&id=SB10296","tags":["Third Party 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List","Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://seclists.org/bugtraq/2019/Sep/18","tags":["Mailing List","Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://security.netapp.com/advisory/ntap-20190823-0005/","tags":["Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://support.f5.com/csp/article/K46011592","tags":["Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://support.f5.com/csp/article/K46011592?utm_source=f5support&amp%3Butm_medium=RSS","source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://www.debian.org/security/2019/dsa-4520","tags":["Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://www.synology.com/security/advisory/Synology_SA_19_33","tags":["Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2019-9518","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."}