The fix for CVE-2019-0199 was incomplete and did not address HTTP/2 connection window exhaustion on write in Apache Tomcat versions 9.0.0.M1 to 9.0.19 and 8.5.0 to 8.5.40 . By not sending WINDOW_UPDATE messages for the connection window (stream 0) clients were able to cause server-side threads to block eventually leading to thread exhaustion and a DoS.
{ "nvd_published_at": "2019-06-21T18:15:00Z", "cwe_ids": [ "CWE-667" ], "severity": "HIGH", "github_reviewed": true, "github_reviewed_at": "2019-06-26T00:56:45Z" }