{"id":"CVE-2025-53506","summary":"Apache Tomcat: DoS via excessive h2 streams at connection start","details":"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.","aliases":["BIT-tomcat-2025-53506","GHSA-25xr-qj8w-c4vf"],"modified":"2026-05-18T05:58:11.074114971Z","published":"2025-07-10T19:14:23.249Z","related":["ALSA-2025:14177","ALSA-2025:14178","ALSA-2025:14181","CGA-37ch-cv83-jr47","SUSE-SU-2025:02745-1","SUSE-SU-2025:02978-1","SUSE-SU-2025:02979-1","SUSE-SU-2025:03024-1","SUSE-SU-2026:1058-1","openSUSE-SU-2025:15440-1","openSUSE-SU-2025:15441-1","openSUSE-SU-2025:15442-1"],"database_specific":{"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/53xxx/CVE-2025-53506.json","unresolved_ranges":[{"source":"AFFECTED_FIELD","extracted_events":[{"introduced":"11.0.0-M1"},{"last_affected":"11.0.8"},{"introduced":"10.1.0-M1"},{"last_affected":"10.1.42"},{"introduced":"9.0.0.M1"},{"last_affected":"9.0.106"},{"introduced":"8.5.0"},{"last_affected":"8.5.100"}]},{"source":"DESCRIPTION","extracted_events":[{"introduced":"11.0.0-M1"},{"fixed":"11.0.8"},{"introduced":"10.1.0-M1"},{"fixed":"10.1.42"},{"introduced":"9.0.0.M1"},{"fixed":"9.0.106"},{"introduced":"8.5.0"},{"fixed":"8.5.100"}]}],"cwe_ids":["CWE-400"],"cna_assigner":"apache"},"references":[{"type":"WEB","url":"http://www.openwall.com/lists/oss-security/2025/07/10/13"},{"type":"WEB","url":"https://lists.debian.org/debian-lts-announce/2025/07/msg00009.html"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/53xxx/CVE-2025-53506.json"},{"type":"ADVISORY","url":"https://lists.apache.org/thread/p09775q0rd185m6zz98krg0fp45j8kr0"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2025-53506"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/apache/tomcat","events":[{"introduced":"16bf392c67833ad549733b58c350ff92b5ee782a"},{"last_affected":"05ccf0c3e22d388f0cf853e32485d8249d051f2f"},{"introduced":"e9d17cddc285615807ec5fef09240777436b25dc"},{"last_affected":"0289da4f342744334e0fc5a53ee958e68024fead"},{"introduced":"56e547d387ab49f688c93fe9ca082b1b5d94deed"},{"last_affected":"8a48dcb90f13f1670632e763e945f4cc9ef869e6"}],"database_specific":{"source":"CPE_FIELD","cpe":"cpe:2.3:a:apache:tomcat:*:*:*:*:*:*:*:*","extracted_events":[{"introduced":"9.0.0"},{"last_affected":"9.0.106"},{"introduced":"10.1.0"},{"last_affected":"10.1.42"},{"introduced":"11.0.0"},{"last_affected":"11.0.8"}]}}],"database_specific":{"source":"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2025-53506.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"}]}