{"id":"CVE-2019-9517","url":"https://www.cyber-defence.io/tools/cve/CVE-2019-9517","generatedAt":"2026-11-05T02:46:48.284Z","title":"Some HTTP/2 implementations are vulnerable to unconstrained interal data buffering, potentially leading to a denial of service.","description":"Some HTTP/2 implementations are vulnerable to unconstrained interal data buffering, potentially leading to a denial of service. The attacker opens the HTTP/2 window so the peer can send without constraint; however, they leave the TCP window closed so the peer cannot actually write (many of) the bytes on the wire. The attacker then sends a stream of requests for a large response object. Depending on how the servers queue the responses, this can consume excess memory, CPU, 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/http server","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/communications element manager","oracle/graalvm","oracle/instantis enterprisetrack","oracle/retail xstore point of service","mcafee/web gateway","netapp/clustered data ontap","nodejs/node.js"],"epss":{"score":0.2789,"percentile":0.98101,"date":"2026-11-03","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 27.9%, 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/msg00004.html","tags":["Mailing List","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":"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://www.openwall.com/lists/oss-security/2019/08/15/7","tags":["Mailing List","Third Party Advisory"],"source":"cret@cert.org"},{"url":"https://access.redhat.com/errata/RHSA-2019:2893","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-2019:2946","tags":["Third Party Advisory"],"source":"cret@cert.org"},{"url":"https://access.redhat.com/errata/RHSA-2019:2949","tags":["Third Party Advisory"],"source":"cret@cert.org"},{"url":"https://access.redhat.com/errata/RHSA-2019:2950","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-2019:3932","tags":["Third Party Advisory"],"source":"cret@cert.org"},{"url":"https://access.redhat.com/errata/RHSA-2019:3933","tags":["Third Party Advisory"],"source":"cret@cert.org"},{"url":"https://access.redhat.com/errata/RHSA-2019:3935","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/4610762456644181b267c846423b3a990bd4aaea1886ecc7d51febdb%40%3Cannounce.httpd.apache.org%3E","source":"cret@cert.org"},{"url":"https://lists.apache.org/thread.html/56c2e7cc9deb1c12a843d0dc251ea7fd3e7e80293cde02fcd65286ba%40%3Ccvs.httpd.apache.org%3E","source":"cret@cert.org"},{"url":"https://lists.apache.org/thread.html/d89f999e26dfb1d50f247ead1fe8538014eb412b2dbe5be4b1a9ef50%40%3Cdev.httpd.apache.org%3E","source":"cret@cert.org"},{"url":"https://lists.apache.org/thread.html/ec97fdfc1a859266e56fef084353a34e0a0b08901b3c1aa317a43c8c%40%3Cdev.httpd.apache.org%3E","source":"cret@cert.org"},{"url":"https://lists.apache.org/thread.html/r03ee478b3dda3e381fd6189366fa7af97c980d2f602846eef935277d%40%3Ccvs.httpd.apache.org%3E","source":"cret@cert.org"},{"url":"https://lists.apache.org/thread.html/r06f0d87ebb6d59ed8379633f36f72f5b1f79cadfda72ede0830b42cf%40%3Ccvs.httpd.apache.org%3E","source":"cret@cert.org"},{"url":"https://lists.apache.org/thread.html/r3c5c3104813c1c5508b55564b66546933079250a46ce50eee90b2e36%40%3Ccvs.httpd.apache.org%3E","source":"cret@cert.org"},{"url":"https://lists.apache.org/thread.html/r76142b8c5119df2178be7c2dba88fde552eedeec37ea993dfce68d1d%40%3Ccvs.httpd.apache.org%3E","source":"cret@cert.org"},{"url":"https://lists.apache.org/thread.html/r9f93cf6dde308d42a9c807784e8102600d0397f5f834890708bf6920%40%3Ccvs.httpd.apache.org%3E","source":"cret@cert.org"},{"url":"https://lists.apache.org/thread.html/rc998b18880df98bafaade071346690c2bc1444adaa1a1ea464b93f0a%40%3Ccvs.httpd.apache.org%3E","source":"cret@cert.org"},{"url":"https://lists.apache.org/thread.html/rd18c3c43602e66f9cdcf09f1de233804975b9572b0456cc582390b6f%40%3Ccvs.httpd.apache.org%3E","source":"cret@cert.org"},{"url":"https://lists.apache.org/thread.html/rd2fb621142e7fa187cfe12d7137bf66e7234abcbbcd800074c84a538%40%3Ccvs.httpd.apache.org%3E","source":"cret@cert.org"},{"url":"https://lists.apache.org/thread.html/re3d27b6250aa8548b8845d314bb8a350b3df326cacbbfdfe4d455234%40%3Ccvs.httpd.apache.org%3E","source":"cret@cert.org"},{"url":"https://lists.apache.org/thread.html/rf6449464fd8b7437704c55f88361b66f12d5b5f90bcce66af4be4ba9%40%3Ccvs.httpd.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/BP556LEG3WENHZI5TAQ6ZEBFTJB4E2IS/","source":"cret@cert.org"},{"url":"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/CMNFX5MNYRWWIMO4BTKYQCGUDMHO3AXP/","source":"cret@cert.org"},{"url":"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/XHTKU7YQ5EEP2XNSAV4M4VJ7QCBOJMOD/","source":"cret@cert.org"},{"url":"https://seclists.org/bugtraq/2019/Aug/47","tags":["Mailing List","Third Party Advisory"],"source":"cret@cert.org"},{"url":"https://security.gentoo.org/glsa/201909-04","tags":["Third Party Advisory"],"source":"cret@cert.org"},{"url":"https://security.netapp.com/advisory/ntap-20190823-0003/","tags":["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://security.netapp.com/advisory/ntap-20190905-0003/","tags":["Third Party Advisory"],"source":"cret@cert.org"},{"url":"https://support.f5.com/csp/article/K02591030","tags":["Third Party Advisory"],"source":"cret@cert.org"},{"url":"https://support.f5.com/csp/article/K02591030?utm_source=f5support&amp%3Butm_medium=RSS","source":"cret@cert.org"},{"url":"https://usn.ubuntu.com/4113-1/","tags":["Third Party Advisory"],"source":"cret@cert.org"},{"url":"https://www.debian.org/security/2019/dsa-4509","tags":["Third Party Advisory"],"source":"cret@cert.org"},{"url":"https://www.oracle.com/security-alerts/cpuapr2020.html","tags":["Third Party Advisory"],"source":"cret@cert.org"},{"url":"https://www.oracle.com/technetwork/security-advisory/cpuoct2019-5072832.html","tags":["Patch","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/msg00004.html","tags":["Mailing List","Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"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://www.openwall.com/lists/oss-security/2019/08/15/7","tags":["Mailing List","Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://access.redhat.com/errata/RHSA-2019:2893","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-2019:2946","tags":["Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://access.redhat.com/errata/RHSA-2019:2949","tags":["Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://access.redhat.com/errata/RHSA-2019:2950","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-2019:3932","tags":["Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://access.redhat.com/errata/RHSA-2019:3933","tags":["Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2019-9517","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."}