High 7.5Published Jun 26, 2020

CVE-2020-11996A specially crafted sequence of HTTP/2 requests sent to Apache Tomcat 10.0.0-M1 to 10.0.0-M5, 9.0.0.M1 to 9.0.35 and 8.5.0 to 8.5.55 could trigger high CPU usage for several seconds.

Updated under an hour ago (Oct 27, 2026, 1:50 AM ET)

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Exploited in the last 30 days

A specially crafted sequence of HTTP/2 requests sent to Apache Tomcat 10.0.0-M1 to 10.0.0-M5, 9.0.0.M1 to 9.0.35 and 8.5.0 to 8.5.55 could trigger high CPU usage for several seconds. If a sufficient number of such requests were made on concurrent HTTP/2 connections, the server could become unresponsive.

CVSS: 7.5 HIGH (v3.1, NVD)CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Weakness (CWE): Not given
Known exploited: Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days): Not loaded for this CVE
Assigned by: apache
NVD analysis: Modified
Record last updated: Oct 8, 2026
First seen by InfoSec Signals: Oct 9, 2026

Affected products

Affected products

Apache Apache Tomcat apache:tomcat (from the name)	10.0.0-M1 to 10.0.0-M5; 9.0.0.M1 to 9.0.35; 8.5.0 to 8.5.55	CNA record
apache tomcat apache:tomcat	from 8.5.0 through 8.5.55; from 9.0.0 through 9.0.35; 9.0.0; 9.0.0; 9.0.0; 9.0.0; 9.0.0; 9.0.0; and 26 more ranges	NVD
canonical ubuntu_linux canonical:ubuntu_linux	20.04	NVD
oracle mysql_enterprise_monitor oracle:mysql_enterprise_monitor	through 8.0.21	NVD
oracle siebel_ui_framework oracle:siebel_ui_framework	through 20.12	NVD
oracle workload_manager oracle:workload_manager	12.2.0.1; 18c; 19c	NVD
opensuse leap opensuse:leap	15.1; 15.2	NVD
debian debian_linux debian:debian_linux	9.0; 10.0	NVD
netapp oncommand_system_manager netapp:oncommand_system_manager	3.0; 3.1.3	NVD

References

References

https://lists.apache.org/thread.html/r5541ef6b6b68b49f76fc4c45695940116da2bcbe0312ef204a00a2e0%40%3Cannounce.tomcat.apache.org%3E	x-refsource-confirm
https://lists.apache.org/thread.html/ra7092f7492569b39b04ec0decf52628ba86c51f15efb38f5853e2760%40%3Cnotifications.ofbiz.apache.org%3E	mailing-list, x-refsource-mlist
https://lists.apache.org/thread.html/rb4ee49ecc4c59620ffd5e66e84a17e526c2c3cfa95d0cd682d90d338%40%3Cnotifications.ofbiz.apache.org%3E	mailing-list, x-refsource-mlist
https://lists.apache.org/thread.html/rb820f1a2a02bf07414be12c653c2ab5321fd87b9bf6c5e635c53ff4b%40%3Cnotifications.ofbiz.apache.org%3E	mailing-list, x-refsource-mlist
https://lists.apache.org/thread.html/r8f7484589454638af527182ae55ef5b628ba00c05c5b11887c922fb1%40%3Cnotifications.ofbiz.apache.org%3E	mailing-list, x-refsource-mlist
https://lists.apache.org/thread.html/r74f5a8204efe574cbfcd95b2a16236fe95beb45c4d9fee3dc789dca9%40%3Ccommits.ofbiz.apache.org%3E	mailing-list, x-refsource-mlist
https://lists.apache.org/thread.html/rea65d6ef2e45dd1c45faae83922042732866c7b88fa109b76c83db52%40%3Cnotifications.ofbiz.apache.org%3E	mailing-list, x-refsource-mlist
https://lists.apache.org/thread.html/rc80b96b4b96618b2b7461cb90664a428cfd6605eea9f74e51b792542%40%3Cnotifications.ofbiz.apache.org%3E	mailing-list, x-refsource-mlist
https://lists.apache.org/thread.html/r93ca628ef3a4530dfe5ac49fddc795f0920a4b2a408b57a30926a42b%40%3Ccommits.ofbiz.apache.org%3E	mailing-list, x-refsource-mlist
https://lists.apache.org/thread.html/r8f3d416c193bc9384a8a7dd368623d441f5fcaff1057115008100561%40%3Ccommits.ofbiz.apache.org%3E	mailing-list, x-refsource-mlist
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The CVE record on cve.org NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.