{"id":"CVE-2020-13943","revision":"4a34c654d1a444f8b72524d876ef1062","records":[{"revision":"4a34c654d1a444f8b72524d876ef1062","observedAt":"2026-10-23T15:48:27.903+00:00","statement":{"source":"cve-program","id":"CVE-2020-13943","aliases":[],"title":"If an HTTP/2 client connecting to Apache Tomcat 10.0.0-M1 to 10.0.0-M7, 9.0.0.M1 to 9.0.37 or 8.5.0 to 8.5.57 exceeded the agreed maximum number of concurrent streams for a connection (in violation of the HTTP/2 protocol), it was possible t…","description":"If an HTTP/2 client connecting to Apache Tomcat 10.0.0-M1 to 10.0.0-M7, 9.0.0.M1 to 9.0.37 or 8.5.0 to 8.5.57 exceeded the agreed maximum number of concurrent streams for a connection (in violation of the HTTP/2 protocol), it was possible that a subsequent request made on that connection could contain HTTP headers - including HTTP/2 pseudo headers - from a previous request rather than the intended headers. This could lead to users seeing responses for unexpected resources.","state":0,"publishedAt":"2020-10-12T13:46:47+00:00","modifiedAt":"2026-10-08T21:13:52.499+00:00","affected":[{"ecosystem":"Vendor product","name":"Apache Tomcat","ranges":[],"versions":[],"rawVersionEvidence":"{\n                    \"product\": \"Apache Tomcat\",\n                    \"vendor\": \"n/a\",\n                    \"versions\": [\n                        {\n                            \"status\": \"affected\",\n                            \"version\": \"Apache Tomcat 10.0.0-M1 to 10.0.0-M7, 9.0.0.M1 to 9.0.37, 8.5.0 to 8.5.57\"\n                        }\n                    ]\n                }"}],"metrics":[],"references":["https://lists.apache.org/thread.html/r4a390027eb27e4550142fac6c8317cc684b157ae314d31514747f307%40%3Cannounce.tomcat.apache.org%3E","https://lists.debian.org/debian-lts-announce/2020/10/msg00019.html","http://lists.opensuse.org/opensuse-security-announce/2020-11/msg00002.html","http://lists.opensuse.org/opensuse-security-announce/2020-11/msg00021.html","https://www.debian.org/security/2021/dsa-4835","https://www.oracle.com/security-alerts/cpuApr2021.html","https://security.netapp.com/advisory/ntap-20201016-0007/"],"sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2020-13943","license":"CVE Program Terms of Use","key":"cve-program:CVE-2020-13943","identifiers":["CVE-2020-13943"]},"retained":false,"historicalAffected":[]}],"coverage":[]}