{"id":"CVE-2025-53506","published":"2025-07-10T19:14:23Z","modified":"2025-11-04T21:11:48Z","title":"Apache Tomcat: DoS via excessive h2 streams at connection start","vendor":"Apache","product":"Apache Tomcat","tier":"tail","description":{"text":"Uncontrolled Resource Consumption vulnerability in Apache Tomcat if an HTTP/2 client did not acknowledge the initial settings frame that reduces the maximum permitted concurrent streams.\n\nThis issue affects Apache Tomcat: from 11.0.0-M1 through 11.0.8, from 10.1.0-M1 through 10.1.42, from 9.0.0.M1 through 9.0.106.\nThe following versions were EOL at the time the CVE was created but are \nknown to be affected: 8.5.0 through 8.5.100. Other EOL versions may also be affected.\n\n\nUsers are recommended to upgrade to version 11.0.9, 10.1.43 or 9.0.107, which fix the issue.","provenance":"source","from":"CVE.org"},"cvss":{"score":7.5,"severity":"HIGH","version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","provenance":"source","from":"CISA ADP Vulnrichment"},"epss":{"score":0.02129,"percentile":0.81948,"provenance":"source"},"cwes":[{"id":"CWE-400","name":"Uncontrolled Resource Consumption"}],"references":[{"url":"https://lists.apache.org/thread/p09775q0rd185m6zz98krg0fp45j8kr0","tags":["vendor-advisory"]},{"url":"https://lists.debian.org/debian-lts-announce/2025/07/msg00009.html","tags":[]},{"url":"http://www.openwall.com/lists/oss-security/2025/07/10/13","tags":[]}],"priority":{"score":21.6,"factors":[{"name":"EPSS percentile","points":16.39},{"name":"CVSS severity","points":5.25}]},"vendorSlug":"apache","affectedVersions":[{"vendor":"Apache Software Foundation","product":"Apache Tomcat","versions":[">= 11.0.0-M1, <= 11.0.8",">= 10.1.0-M1, <= 10.1.42",">= 9.0.0.M1, <= 9.0.106",">= 8.5.0, <= 8.5.100"]}],"affected":[{"ecosystem":"Maven","package":"org.apache.tomcat:tomcat-coyote","vulnerableRanges":[">=11.0.0-M1, <11.0.9",">=10.1.0-M1, <10.1.43",">=9.0.0.M1, <9.0.107",">=8.5.0, <=8.5.100"],"patched":["11.0.9","10.1.43","9.0.107"],"from":["GHSA-25xr-qj8w-c4vf"],"provenance":"source"},{"ecosystem":"Maven","package":"org.apache.tomcat.embed:tomcat-embed-core","vulnerableRanges":[">=8.5.0, <=8.5.100",">=9.0.0.M1, <9.0.107",">=10.1.0-M1, <10.1.43",">=11.0.0-M1, <11.0.9"],"patched":["9.0.107","10.1.43","11.0.9"],"from":["GHSA-25xr-qj8w-c4vf"],"provenance":"source"}],"euvd":{"id":"EUVD-2025-21032","exploited":false,"provenance":"source"},"lineage":{"packageHistory":[{"cve":"CVE-2023-24998","published":"2023-02-20","fixed":"11.0.0-M5","kev":false},{"cve":"CVE-2024-52317","published":"2024-11-18","fixed":"11.0.0","kev":false},{"cve":"CVE-2025-31650","published":"2025-04-28","fixed":"11.0.6","kev":false,"link":{"from":"CVE-2025-31650","to":"CVE-2025-53506","relation":"successor","confidence":"low","kind":"sequence","evidence":[{"kind":"version-step","provenance":"source","package":"Maven:org.apache.tomcat:tomcat-coyote","fromFixed":"9.0.104","toFixed":"9.0.107","daysApart":73},{"kind":"version-step","provenance":"source","package":"Maven:org.apache.tomcat:tomcat-coyote","fromFixed":"10.1.40","toFixed":"10.1.43","daysApart":73}]}},{"cve":"CVE-2025-53506","published":"2025-07-10","fixed":"11.0.9","kev":false},{"cve":"CVE-2025-48989","published":"2025-08-13","fixed":"11.0.10","kev":false,"link":{"from":"CVE-2025-53506","to":"CVE-2025-48989","relation":"successor","confidence":"low","kind":"sequence","evidence":[{"kind":"version-step","provenance":"source","package":"Maven:org.apache.tomcat.embed:tomcat-embed-core","fromFixed":"9.0.107","toFixed":"9.0.108","daysApart":34},{"kind":"version-step","provenance":"source","package":"Maven:org.apache.tomcat.embed:tomcat-embed-core","fromFixed":"10.1.43","toFixed":"10.1.44","daysApart":34}]}},{"cve":"CVE-2025-66614","published":"2026-02-17","fixed":"11.0.15","kev":false},{"cve":"CVE-2026-24733","published":"2026-02-17","fixed":"11.0.15","kev":false}],"package":"Maven:org.apache.tomcat:tomcat-coyote"}}