ASA-2019-00169 – Apache HTTP Server: mod_http2, possible crash on late upgrade

When HTTP/2 was enabled for a http: host or H2Upgrade was enabled for h2 on a https: host, an Upgrade request from http/1.1 to http/2 that was not the first request on a connection could lead to a misconfiguration and crash. Servers that never enabled the h2 protocol or only enabled it for https: and did not set"H2Upgrade on" are unaffected by this issue.