CVE-2020-13934: Apache Tomcat

High severity, CVSS 7.5. EPSS: 64.1% chance of exploitation in the next 30 days.

An h2c direct connection to Apache Tomcat 10.0.0-M1 to 10.0.0-M6, 9.0.0.M5 to 9.0.36 and 8.5.1 to 8.5.56 did not release the HTTP/1.1 processor after the upgrade to HTTP/2. If a sufficient number of such requests were made, an OutOfMemoryException could occur leading to a denial of service.

Affected products

• Apache Tomcat: from 8.5.1, up to and including 8.5.56; from 9.0.1, up to and including 9.0.36; version 9.0.0 only; version 10.0.0 only
• Canonical Ubuntu Linux: version 20.04 only
• Debian Debian Linux: version 9.0 only; version 10.0 only
• Netapp Oncommand System Manager: from 3.0.0, up to and including 3.1.3
• Opensuse Leap: version 15.1 only; version 15.2 only
• Oracle Agile Engineering Data Management: version 6.2.1.0 only
• Oracle Agile Product Lifecycle Management: version 9.3.3 only; version 9.3.5 only; version 9.3.6 only
• Oracle Communications Instant Messaging Server: version 10.0.1.5.0 only
• Oracle Fmw Platform: version 12.2.1.3.0 only; version 12.2.1.4.0 only
• Oracle Instantis Enterprisetrack: version 17.1 only; version 17.2 only; version 17.3 only
• Oracle Managed File Transfer: version 12.2.1.3.0 only; version 12.2.1.4.0 only
• Oracle MySQL Enterprise Monitor: up to and including 8.0.21
• Oracle Siebel UI Framework: up to and including 20.12
• Oracle Workload Manager: version 12.2.0.1 only; version 18c only; version 19c only

Published 2020-07-14. Last modified 2026-10-08.