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CVE-2020-11996 High

CVE-2020-11996

A specially crafted sequence of HTTP/2 requests sent to Apache Tomcat 10.0.0 to 10.0.0, 9.0.0 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.

Exploit probability 26.7%
Published March 6, 2024
Required by Not available
Last source change March 20, 2026

02 / AFFECTED SOFTWARE

Affected packages

Unknown Unknown

32 explicit affected versions

Maven org.apache.tomcat.embed:tomcat-embed-core

91 explicit affected versions

Maven org.apache.tomcat:tomcat

91 explicit affected versions

Bitnami tomcat

03 / CONNECTIONS

Connected vulnerabilities

04 / EVIDENCE

Source records

Open Source Vulnerabilities CVE-2020-11996

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.

View original source
Open Source Vulnerabilities GHSA-53hp-jpwq-2jgq

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.

View original source
Open Source Vulnerabilities BIT-tomcat-2020-11996

A specially crafted sequence of HTTP/2 requests sent to Apache Tomcat 10.0.0 to 10.0.0, 9.0.0 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.

View original source

05 / REFERENCES

Further evidence