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.
Severity
High 7.5
Published
21 Jun 2019
Last changed
17 Jun 2026
Added to UpHeron
21 Oct 2026
Sources
NVD
Affected software
Software
Affected versions
Apache TomcatServers and applications · cpe:a:apache:tomcat