Apache HTTP Server versions 2.4.20 to 2.4.43 When trace/debug was enabled for the HTTP/2 module and on certain traffic edge patterns, logging statements were made on the wrong connection, causing concurrent use of memory pools. Configuring the LogLevel of mod_http2 above "info" will mitigate this vulnerability for unpatched servers.
https://www.oracle.com/security-alerts/cpuoct2020.html
https://www.oracle.com/security-alerts/cpujan2021.html
https://www.debian.org/security/2020/dsa-4757
https://usn.ubuntu.com/4458-1/
https://security.netapp.com/advisory/ntap-20200814-0005/
https://security.gentoo.org/glsa/202008-04
https://httpd.apache.org/security/vulnerabilities_24.html#CVE-2020-11993
http://packetstormsecurity.com/files/160393/Apache-2-HTTP2-Module-Concurrent-Pool-Usage.html
http://lists.opensuse.org/opensuse-security-announce/2020-10/msg00081.html
http://lists.opensuse.org/opensuse-security-announce/2020-08/msg00071.html
http://lists.opensuse.org/opensuse-security-announce/2020-08/msg00068.html