CVE-2019-9513: Some HTTP/2 implementations are vulnerable to resource loops, potentially leading to a denial of service
Vulnerability summary
CVE-2019-9513 is a high (CVSS 7.8) Uncontrolled Resource Consumption vulnerability in apache traffic_server. EPSS estimates a 81.56% chance of exploitation in the next 30 days, higher than 99.6% of scored vulnerabilities.
Severe, CVSS 7.5 (CVE.org); no exploitation reported by the 5 checked sources; EPSS 82% (FIRST, 03-11-2026)
Source freshness unavailable
How is this decided?Advisory lineage
Upstream 0 · Downstream 36 · Duplicates 1 · Related 17Timeline
- 13-08-2019PublishedVulnerability first disclosed.
- 04-08-2024Last modifiedVulnerability information updated.
Description
Some HTTP/2 implementations are vulnerable to resource loops, potentially leading to a denial of service. The attacker creates multiple request streams and continually shuffles the priority of the streams in a way that causes substantial churn to the priority tree. This can consume excess CPU.
CVSS metrics
8 scores · 5 sources · 3 versions- OSV · UbuntuEcosystem advisory · calculated7.5HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- OSV · DebianEcosystem advisory · calculated7.5HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- NVDNIST7.5HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- OSV · UbuntuEcosystem advisory · calculated7.5HighCVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- NVDNIST7.5HighCVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
EPSS trend
Probability
81.56%
Chance of exploitation in the next 30 days
Percentile
100%
Versus all other CVEs
30-day change
No change 0.00 pp
From 81.56% on 04-10-2026
Known exploited
Compare KEV catalogsNot in the CISA KEV catalog.
Not in the ENISA CNW catalog.
Not in the CIRCL catalog.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root causeAffected systems
Known conditions: network-reachable, no authentication, no user interaction (CVSS vector). Other conditions: not stated in public data.
Redhat6 products
- enterprise_linux8.0
- jboss_core_services1.0
- jboss_enterprise_application_platform7.2.0 | 7.3.0
- openshift_service_mesh1.0
- quay3.0.0
Debian4 products
- nghttp2< 1.39.2-1
- nginx< 1.14.2-3
- nodejs< 10.16.3~dfsg-1
- debian_linuxEOL9.0 | 10.0
Alpine3 products
- nghttp2< 1.39.2-r0 | < 1.35.1-r1
- nginx≥ 1.9.5, < 1.16.1-r0 | ≥ 1.9.5, < 1.14.1-r1 | ≥ 1.9.5, < 1.14.1-r2
- nodejs< 10.16.3-r0
Synology3 products
Ubuntu3 products
- nghttp2< 1.7.1-1ubuntu0.1~esm2 | < 1.30.0-1ubuntu1+esm2
- nginx< 1.10.3-0ubuntu0.16.04.4 | < 1.14.0-0ubuntu1.4
- nodejsAll versions (No fix recorded)
Oracle2 products
- enterprise_communications_broker3.1.0 | 3.2.0
- graalvm19.2.0
Apache1 product
- traffic_server≥ 6.0.0, ≤ 6.2.3 | ≥ 7.0.0, ≤ 7.1.6 | ≥ 8.0.0, ≤ 8.0.3
Apple1 product
- swiftnio≥ 1.0.0, ≤ 1.4.0
Canonical1 product
- ubuntu_linuxEOL16.04 | 18.04 | 19.04
F51 product
- nginx≥ 1.9.5, < 1.16.1 | ≥ 1.17.0, ≤ 1.17.2
Fedoraproject1 product
- fedoraEOL30 | 29
Mcafee1 product
- web_gateway≥ 7.7.2.0, < 7.7.2.24 | ≥ 7.8.2.0, < 7.8.2.13 | ≥ 8.1.0, < 8.2.0
Nodejs1 product
- node.js≥ 8.0.0, ≤ 8.8.1 | ≥ 8.9.0, < 8.16.1 | ≥ 10.0.0, ≤ 10.12.0 | ≥ 10.13.0, < 10.16.3 | ≥ 12.0.0, < 12.8.1
Opensuse1 product
- leapEOL15.0 | 15.1
14 vendors · 29 products
References
52 linksShow all 52 references
- lists.opensuse.org/opensuse-security-announce/2019-09/msg00035.htmlVendor AdvisoryX Refsource SUSEMailing ListThird Party Advisory
- lists.opensuse.org/opensuse-security-announce/2019-09/msg00032.htmlVendor AdvisoryX Refsource SUSEMailing ListThird Party Advisory
- lists.opensuse.org/opensuse-security-announce/2019-09/msg00031.htmlVendor AdvisoryX Refsource SUSEMailing ListThird Party Advisory
- lists.opensuse.org/opensuse-security-announce/2019-10/msg00003.htmlVendor AdvisoryX Refsource SUSEMailing ListThird Party Advisory
- lists.opensuse.org/opensuse-security-announce/2019-10/msg00005.htmlVendor AdvisoryX Refsource SUSEMailing ListThird Party Advisory
- lists.opensuse.org/opensuse-security-announce/2019-10/msg00014.htmlVendor AdvisoryX Refsource SUSEMailing ListThird Party Advisory
- github.com/Netflix/security-bulletins/blob/master/advisories/third-party/2019-002.mdX Refsource MISCREPORTThird Party Advisory