{"id":"CVE-2026-78437","state":"PUBLISHED","title":"Apache Tomcat: HTTP/2 DoS via malformed request","description":"Incomplete cleanup vulnerability in Apache Tomcat allows a malformed request to potentially (depends on timing) cause one request from another user to fail.\n\n\n\nThis issue affects Apache Tomcat: from 11.0.19 through 11.0.25, from 10.1.53 through 10.1.59, from 9.0.116 through 9.0.121.\n\n\n\nUsers are recommended to upgrade to version 11.0.26, 10.1.60 or 9.0.122, which fix the issue.","publishedAt":"2026-09-23T11:26:29.362Z","updatedAt":"2026-09-23T18:10:46.744Z","severity":{"score":7.3,"label":"High","version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L","source":"CISA-ADP"},"assigner":"apache","products":["Apache Software Foundation Apache Tomcat"],"affected":[{"vendor":"Apache Software Foundation","product":"Apache Tomcat","defaultStatus":"unaffected","versions":[{"version":"11.0.19","status":"affected","lessThanOrEqual":"11.0.25","versionType":"semver"},{"version":"10.1.53","status":"affected","lessThanOrEqual":"10.1.59","versionType":"semver"},{"version":"9.0.116","status":"affected","lessThanOrEqual":"9.0.121","versionType":"semver"},{"version":"0","status":"unaffected","lessThanOrEqual":"8.5.100","versionType":"semver"}]}],"references":["https://lists.apache.org/thread/qkmsos3s8chn5053qr466rzwv6sk5gjg","http://www.openwall.com/lists/oss-security/2026/09/23/26"],"weaknesses":["CWE-459"],"ingestedAt":"2026-10-29T20:13:07.220Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/78xxx/CVE-2026-78437.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-78437","state":"PUBLISHED","datePublished":"2026-09-23T11:26:29.362Z","dateUpdated":"2026-09-23T18:10:46.744Z","assignerShortName":"apache","assignerOrgId":"f0158376-9dc2-43b6-827c-5f631a4d8d09","dateReserved":"2026-08-24T16:10:49.885Z"},"containers":{"cna":{"title":"Apache Tomcat: HTTP/2 DoS via malformed request","descriptions":[{"lang":"en","value":"Incomplete cleanup vulnerability in Apache Tomcat allows a malformed request to potentially (depends on timing) cause one request from another user to fail.\n\n\n\nThis issue affects Apache Tomcat: from 11.0.19 through 11.0.25, from 10.1.53 through 10.1.59, from 9.0.116 through 9.0.121.\n\n\n\nUsers are recommended to upgrade to version 11.0.26, 10.1.60 or 9.0.122, which fix the issue."}],"affected":[{"vendor":"Apache Software Foundation","product":"Apache Tomcat","defaultStatus":"unaffected","versions":[{"version":"11.0.19","status":"affected","lessThanOrEqual":"11.0.25","versionType":"semver"},{"version":"10.1.53","status":"affected","lessThanOrEqual":"10.1.59","versionType":"semver"},{"version":"9.0.116","status":"affected","lessThanOrEqual":"9.0.121","versionType":"semver"},{"version":"0","status":"unaffected","lessThanOrEqual":"8.5.100","versionType":"semver"}]}],"references":[{"url":"https://lists.apache.org/thread/qkmsos3s8chn5053qr466rzwv6sk5gjg","tags":["vendor-advisory"]}],"metrics":[{"other":{"type":"Textual description of severity","content":{"text":"low"}},"scenarios":[{"lang":"en","value":"GENERAL"}]}],"problemTypes":[{"descriptions":[{"cweId":"CWE-459","description":"CWE-459 Incomplete cleanup","lang":"en","type":"CWE"}]}],"providerMetadata":{"shortName":"apache","orgId":"f0158376-9dc2-43b6-827c-5f631a4d8d09","dateUpdated":"2026-09-23T11:26:29.362Z"},"source":{"discovery":"INTERNAL"},"x_generator":{"engine":"Vulnogram 1.0.3"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"cvssV3_1":{"scope":"UNCHANGED","version":"3.1","baseScore":7.3,"attackVector":"NETWORK","baseSeverity":"HIGH","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L","integrityImpact":"LOW","userInteraction":"NONE","attackComplexity":"LOW","availabilityImpact":"LOW","privilegesRequired":"NONE","confidentialityImpact":"LOW"}},{"other":{"type":"ssvc","content":{"timestamp":"2026-09-23T16:25:38.365317Z","id":"CVE-2026-78437","options":[{"Exploitation":"none"},{"Automatable":"yes"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-09-23T16:25:54.815Z"}},{"title":"CVE Program Container","references":[{"url":"http://www.openwall.com/lists/oss-security/2026/09/23/26"}],"providerMetadata":{"shortName":"CVE","orgId":"af854a3a-2127-422b-91ae-364da2661108","dateUpdated":"2026-09-23T18:10:46.744Z"}}]}}}