{"id":"CVE-2025-53506","url":"https://www.cyber-defence.io/tools/cve/CVE-2025-53506","generatedAt":"2026-10-28T04:45:59.893Z","title":"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.","description":"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.","published":"2025-07-10T20:15:27.000Z","lastModified":"2026-06-17T09:38:21.000Z","status":"Modified","sourceIdentifier":"security@apache.org","cvss":{"version":"3.1","score":7.5,"severity":"HIGH","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"},"cwe":["CWE-400"],"affected":["apache/tomcat"],"epss":{"score":0.02129,"percentile":0.8185,"date":"2026-10-27","history":[]},"kev":{"listed":false},"exploits":{"count":0,"verified":false,"firstPublished":null,"source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[]},"verdict":{"level":"high","text":"High impact if exploited, but EPSS currently rates exploitation as unlikely (2.13%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit."},"changes":[],"references":[{"url":"https://lists.apache.org/thread/p09775q0rd185m6zz98krg0fp45j8kr0","tags":["Issue Tracking","Mailing List","Vendor Advisory"],"source":"security@apache.org"},{"url":"http://www.openwall.com/lists/oss-security/2025/07/10/13","source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://lists.debian.org/debian-lts-announce/2025/07/msg00009.html","source":"af854a3a-2127-422b-91ae-364da2661108"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2025-53506","epss":"https://www.first.org/epss/","kev":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","exploitdb":"https://www.exploit-db.com/"},"licence":"CC BY 4.0 — link back to the CVE Explorer if you publish the results; upstream data remains subject to its own terms."}