--- id: CVE-2020-13934 title: >- 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 summary: >- 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 OutOfMemor… severity: high cvss: 7.5 cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H' cwe: - CWE-401 - CWE-476 vendor: apache product: tomcat affected: - 'tomcat >= 8.5.1, <= 8.5.56' - 'tomcat >= 9.0.1, <= 9.0.36' - tomcat = 9.0.0 - tomcat = 10.0.0 - debian_linux = 9.0 - debian_linux = 10.0 - 'oncommand_system_manager >= 3.0.0, <= 3.1.3' - leap = 15.1 - leap = 15.2 - ubuntu_linux = 20.04 - agile_engineering_data_management = 6.2.1.0 - agile_product_lifecycle_management = 9.3.3 - agile_product_lifecycle_management = 9.3.5 - agile_product_lifecycle_management = 9.3.6 - communications_instant_messaging_server = 10.0.1.5.0 - fmw_platform = 12.2.1.3.0 - fmw_platform = 12.2.1.4.0 - instantis_enterprisetrack = 17.1 - instantis_enterprisetrack = 17.2 - instantis_enterprisetrack = 17.3 - managed_file_transfer = 12.2.1.3.0 - managed_file_transfer = 12.2.1.4.0 - mysql_enterprise_monitor <= 8.0.21 - siebel_ui_framework <= 20.12 - workload_manager = 12.2.0.1 - workload_manager = 18c - workload_manager = 19c published: '2020-07-14' updated: '2026-08-25' source: NVD sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2020-13934' references: - url: 'http://lists.opensuse.org/opensuse-security-announce/2020-07/msg00084.html' label: security@apache.org - url: 'http://lists.opensuse.org/opensuse-security-announce/2020-07/msg00088.html' label: security@apache.org - url: >- https://lists.apache.org/thread.html/r61f411cf82488d6ec213063fc15feeeb88e31b0ca9c29652ee4f962e%40%3Cannounce.tomcat.apache.org%3E label: security@apache.org - url: >- https://lists.apache.org/thread.html/ra072b1f786e7d139e86f1d1145572e0ff71cef38a96d9c6f5362aac8%40%3Cdev.tomcat.apache.org%3E label: security@apache.org - url: 'https://lists.debian.org/debian-lts-announce/2020/07/msg00017.html' label: security@apache.org - url: 'https://security.netapp.com/advisory/ntap-20200724-0003/' label: security@apache.org - url: 'https://usn.ubuntu.com/4596-1/' label: security@apache.org - url: 'https://www.debian.org/security/2020/dsa-4727' label: security@apache.org - url: 'https://www.oracle.com//security-alerts/cpujul2021.html' label: security@apache.org - url: 'https://www.oracle.com/security-alerts/cpuApr2021.html' label: security@apache.org - url: 'https://www.oracle.com/security-alerts/cpujan2021.html' label: security@apache.org - url: 'https://www.oracle.com/security-alerts/cpujan2022.html' label: security@apache.org - url: 'https://www.oracle.com/security-alerts/cpuoct2020.html' label: security@apache.org - url: 'http://lists.opensuse.org/opensuse-security-announce/2020-07/msg00084.html' label: af854a3a-2127-422b-91ae-364da2661108 - url: 'http://lists.opensuse.org/opensuse-security-announce/2020-07/msg00088.html' label: af854a3a-2127-422b-91ae-364da2661108 - url: >- https://lists.apache.org/thread.html/r61f411cf82488d6ec213063fc15feeeb88e31b0ca9c29652ee4f962e%40%3Cannounce.tomcat.apache.org%3E label: af854a3a-2127-422b-91ae-364da2661108 - url: >- https://lists.apache.org/thread.html/ra072b1f786e7d139e86f1d1145572e0ff71cef38a96d9c6f5362aac8%40%3Cdev.tomcat.apache.org%3E label: af854a3a-2127-422b-91ae-364da2661108 - url: 'https://lists.debian.org/debian-lts-announce/2020/07/msg00017.html' label: af854a3a-2127-422b-91ae-364da2661108 - url: 'https://security.netapp.com/advisory/ntap-20200724-0003/' label: af854a3a-2127-422b-91ae-364da2661108 - url: 'https://usn.ubuntu.com/4596-1/' label: af854a3a-2127-422b-91ae-364da2661108 - url: 'https://www.debian.org/security/2020/dsa-4727' label: af854a3a-2127-422b-91ae-364da2661108 - url: 'https://www.oracle.com//security-alerts/cpujul2021.html' label: af854a3a-2127-422b-91ae-364da2661108 - url: 'https://www.oracle.com/security-alerts/cpuApr2021.html' label: af854a3a-2127-422b-91ae-364da2661108 - url: 'https://www.oracle.com/security-alerts/cpujan2021.html' label: af854a3a-2127-422b-91ae-364da2661108 - url: 'https://www.oracle.com/security-alerts/cpujan2022.html' label: af854a3a-2127-422b-91ae-364da2661108 - url: 'https://www.oracle.com/security-alerts/cpuoct2020.html' label: af854a3a-2127-422b-91ae-364da2661108 tags: - nvd epss: 0.64124 epssPercentile: 0.99201 ingestedAt: '2026-08-25T17:29:30.185Z' --- ## Overview 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 - `tomcat >= 8.5.1, <= 8.5.56` - `tomcat >= 9.0.1, <= 9.0.36` - `tomcat = 9.0.0` - `tomcat = 10.0.0` - `debian_linux = 9.0` - `debian_linux = 10.0` - `oncommand_system_manager >= 3.0.0, <= 3.1.3` - `leap = 15.1` - `leap = 15.2` - `ubuntu_linux = 20.04` - `agile_engineering_data_management = 6.2.1.0` - `agile_product_lifecycle_management = 9.3.3` - `agile_product_lifecycle_management = 9.3.5` - `agile_product_lifecycle_management = 9.3.6` - `communications_instant_messaging_server = 10.0.1.5.0` - `fmw_platform = 12.2.1.3.0` - `fmw_platform = 12.2.1.4.0` - `instantis_enterprisetrack = 17.1` - `instantis_enterprisetrack = 17.2` - `instantis_enterprisetrack = 17.3` - `managed_file_transfer = 12.2.1.3.0` - `managed_file_transfer = 12.2.1.4.0` - `mysql_enterprise_monitor <= 8.0.21` - `siebel_ui_framework <= 20.12` - `workload_manager = 12.2.0.1` - `workload_manager = 18c` - `workload_manager = 19c` ## Remediation Refer to the linked advisories for vendor-supplied fixes and affected version ranges.