GHSA-qcxh-w3j9-58qrHighCVSS 7.5

Apache Tomcat Denial of Service vulnerability

Published
June 15, 2020
Last Modified
May 20, 2026

🔗 CVE IDs covered (1)

📋 Description

The HTTP/2 implementation in Apache Tomcat 9.0.0.M1 to 9.0.14 and 8.5.0 to 8.5.37 accepted streams with excessive numbers of SETTINGS frames and also permitted clients to keep streams open without reading/writing request/response data. By keeping streams open for requests that utilised the Servlet API's blocking I/O, clients were able to cause server-side threads to block eventually leading to thread exhaustion and a DoS.

🎯 Affected products4

  • maven/org.apache.tomcat.embed:tomcat-embed-core:>= 9.0.0, < 9.0.16
  • maven/org.apache.tomcat.embed:tomcat-embed-core:>= 8.0.0, < 8.5.38
  • maven/org.apache.tomcat:tomcat-coyote:>= 9.0.0, < 9.0.16
  • maven/org.apache.tomcat:tomcat-coyote:>= 8.0.0, < 8.5.38

🔗 References (59)