High 7.5Published Jul 14, 2020

CVE-2020-13934An 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.

Updated under an hour ago (Oct 27, 2026, 3:40 PM ET)

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No exploitation reported and no EPSS estimate yet.

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Exploited in the last 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.

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 tomcat apache:tomcat	from 8.5.1 through 8.5.56; from 9.0.1 through 9.0.36; 9.0.0; 9.0.0; 9.0.0; 9.0.0; 9.0.0; 9.0.0; and 23 more ranges	NVD
debian debian_linux debian:debian_linux	9.0; 10.0	NVD
netapp oncommand_system_manager netapp:oncommand_system_manager	from 3.0.0 through 3.1.3	NVD
opensuse leap opensuse:leap	15.1; 15.2	NVD
canonical ubuntu_linux canonical:ubuntu_linux	20.04	NVD
oracle agile_engineering_data_management oracle:agile_engineering_data_management	6.2.1.0	NVD
oracle agile_product_lifecycle_management oracle:agile_product_lifecycle_management	9.3.3; 9.3.5; 9.3.6	NVD
oracle communications_instant_messaging_server oracle:communications_instant_messaging_server	10.0.1.5.0	NVD
oracle fmw_platform oracle:fmw_platform	12.2.1.3.0; 12.2.1.4.0	NVD
oracle instantis_enterprisetrack oracle:instantis_enterprisetrack	17.1; 17.2; 17.3	NVD
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References

References

https://lists.apache.org/thread.html/r61f411cf82488d6ec213063fc15feeeb88e31b0ca9c29652ee4f962e%40%3Cannounce.tomcat.apache.org%3E	x-refsource-misc
https://www.debian.org/security/2020/dsa-4727	vendor-advisory, x-refsource-debian
https://lists.debian.org/debian-lts-announce/2020/07/msg00017.html	mailing-list, x-refsource-mlist
http://lists.opensuse.org/opensuse-security-announce/2020-07/msg00084.html	vendor-advisory, x-refsource-suse
http://lists.opensuse.org/opensuse-security-announce/2020-07/msg00088.html	vendor-advisory, x-refsource-suse
https://lists.apache.org/thread.html/ra072b1f786e7d139e86f1d1145572e0ff71cef38a96d9c6f5362aac8%40%3Cdev.tomcat.apache.org%3E	mailing-list, x-refsource-mlist
https://www.oracle.com/security-alerts/cpuoct2020.html	x-refsource-misc
https://security.netapp.com/advisory/ntap-20200724-0003/	x-refsource-confirm
https://usn.ubuntu.com/4596-1/	vendor-advisory, x-refsource-ubuntu
https://www.oracle.com/security-alerts/cpujan2021.html	x-refsource-misc
1–10 of 13

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.