{"api_version":"1","generated_at":"2026-10-01T04:01:47+00:00","cve":"CVE-2026-78437","urls":{"html":"https://cve.report/CVE-2026-78437","api":"https://cve.report/api/cve/CVE-2026-78437.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2026-78437","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-78437"},"summary":{"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.","state":"PUBLISHED","assigner":"apache","published_at":"2026-09-23 12:17:07","updated_at":"2026-09-23 19:19:21"},"problem_types":["CWE-459","CWE-459 CWE-459 Incomplete cleanup"],"metrics":[{"version":"3.1","source":"ADP","type":"DECLARED","score":"7.3","severity":"HIGH","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L","data":{"attackComplexity":"LOW","attackVector":"NETWORK","availabilityImpact":"LOW","baseScore":7.3,"baseSeverity":"HIGH","confidentialityImpact":"LOW","integrityImpact":"LOW","privilegesRequired":"NONE","scope":"UNCHANGED","userInteraction":"NONE","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L","version":"3.1"}},{"version":"3.1","source":"134c704f-9b21-4f2e-91b3-4a467353bcc0","type":"Secondary","score":"7.3","severity":"HIGH","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L","data":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L","baseScore":7.3,"baseSeverity":"HIGH","attackVector":"NETWORK","attackComplexity":"LOW","privilegesRequired":"NONE","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"LOW","integrityImpact":"LOW","availabilityImpact":"LOW"}}],"references":[{"url":"http://www.openwall.com/lists/oss-security/2026/09/23/26","name":"http://www.openwall.com/lists/oss-security/2026/09/23/26","refsource":"af854a3a-2127-422b-91ae-364da2661108","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://lists.apache.org/thread/qkmsos3s8chn5053qr466rzwv6sk5gjg","name":"https://lists.apache.org/thread/qkmsos3s8chn5053qr466rzwv6sk5gjg","refsource":"security@apache.org","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-78437","name":"CVE Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-78437","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[{"source":"CNA","vendor":"Apache Software Foundation","product":"Apache Tomcat","version":"affected 11.0.19 11.0.25 semver","platforms":[]},{"source":"CNA","vendor":"Apache Software Foundation","product":"Apache Tomcat","version":"affected 10.1.53 10.1.59 semver","platforms":[]},{"source":"CNA","vendor":"Apache Software Foundation","product":"Apache Tomcat","version":"affected 9.0.116 9.0.121 semver","platforms":[]},{"source":"CNA","vendor":"Apache Software Foundation","product":"Apache Tomcat","version":"unaffected 8.5.100 semver","platforms":[]}],"timeline":[],"solutions":[],"workarounds":[],"exploits":[],"credits":[],"nvd_cpes":[],"vendor_comments":[],"enrichments":{"kev":null,"epss":{"cve_year":"2026","cve_id":"78437","cve":"CVE-2026-78437","epss":"0.002600000","percentile":"0.156860000","score_date":"2026-09-24","updated_at":"2026-09-25 00:02:55"},"legacy_qids":[]},"source_records":{"cve_program":{"containers":{"adp":[{"metrics":[{"cvssV3_1":{"attackComplexity":"LOW","attackVector":"NETWORK","availabilityImpact":"LOW","baseScore":7.3,"baseSeverity":"HIGH","confidentialityImpact":"LOW","integrityImpact":"LOW","privilegesRequired":"NONE","scope":"UNCHANGED","userInteraction":"NONE","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L","version":"3.1"}},{"other":{"content":{"id":"CVE-2026-78437","options":[{"Exploitation":"none"},{"Automatable":"yes"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","timestamp":"2026-09-23T16:25:38.365317Z","version":"2.0.3"},"type":"ssvc"}}],"providerMetadata":{"dateUpdated":"2026-09-23T16:25:54.815Z","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","shortName":"CISA-ADP"},"title":"CISA ADP Vulnrichment"},{"providerMetadata":{"dateUpdated":"2026-09-23T18:10:46.744Z","orgId":"af854a3a-2127-422b-91ae-364da2661108","shortName":"CVE"},"references":[{"url":"http://www.openwall.com/lists/oss-security/2026/09/23/26"}],"title":"CVE Program Container"}],"cna":{"affected":[{"defaultStatus":"unaffected","product":"Apache Tomcat","vendor":"Apache Software Foundation","versions":[{"lessThanOrEqual":"11.0.25","status":"affected","version":"11.0.19","versionType":"semver"},{"lessThanOrEqual":"10.1.59","status":"affected","version":"10.1.53","versionType":"semver"},{"lessThanOrEqual":"9.0.121","status":"affected","version":"9.0.116","versionType":"semver"},{"lessThanOrEqual":"8.5.100","status":"unaffected","version":"0","versionType":"semver"}]}],"descriptions":[{"lang":"en","supportingMedia":[{"base64":false,"type":"text/html","value":"<p>Incomplete cleanup vulnerability in Apache Tomcat allows a malformed request to potentially (depends on timing) cause one request from another user to fail.</p><p>This 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.</p><p>Users are recommended to upgrade to version 11.0.26, 10.1.60 or 9.0.122, which fix the issue.</p>"}],"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."}],"metrics":[{"other":{"content":{"text":"low"},"type":"Textual description of severity"},"scenarios":[{"lang":"en","value":"GENERAL"}]}],"problemTypes":[{"descriptions":[{"cweId":"CWE-459","description":"CWE-459 Incomplete cleanup","lang":"en","type":"CWE"}]}],"providerMetadata":{"dateUpdated":"2026-09-23T11:26:29.362Z","orgId":"f0158376-9dc2-43b6-827c-5f631a4d8d09","shortName":"apache"},"references":[{"tags":["vendor-advisory"],"url":"https://lists.apache.org/thread/qkmsos3s8chn5053qr466rzwv6sk5gjg"}],"source":{"discovery":"INTERNAL"},"title":"Apache Tomcat: HTTP/2 DoS via malformed request","x_generator":{"engine":"Vulnogram 1.0.3"}}},"cveMetadata":{"assignerOrgId":"f0158376-9dc2-43b6-827c-5f631a4d8d09","assignerShortName":"apache","cveId":"CVE-2026-78437","datePublished":"2026-09-23T11:26:29.362Z","dateReserved":"2026-08-24T16:10:49.885Z","dateUpdated":"2026-09-23T18:10:46.744Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"},"nvd":{"publishedDate":"2026-09-23 12:17:07","lastModifiedDate":"2026-09-23 19:19:21","problem_types":["CWE-459","CWE-459 CWE-459 Incomplete cleanup"],"metrics":{"cvssMetricV31":[{"source":"134c704f-9b21-4f2e-91b3-4a467353bcc0","type":"Secondary","cvssData":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L","baseScore":7.3,"baseSeverity":"HIGH","attackVector":"NETWORK","attackComplexity":"LOW","privilegesRequired":"NONE","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"LOW","integrityImpact":"LOW","availabilityImpact":"LOW"},"exploitabilityScore":3.9,"impactScore":3.4}],"ssvcV203":[{"source":"134c704f-9b21-4f2e-91b3-4a467353bcc0","ssvcData":{"timestamp":"2026-09-23T16:25:38.365317Z","id":"CVE-2026-78437","options":[{"exploitation":"none"},{"automatable":"yes"},{"technicalImpact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}]},"configurations":[]},"legacy_mitre":{"record":{"CveYear":"2026","CveId":"78437","Ordinal":"1","Title":"Apache Tomcat: HTTP/2 DoS via malformed request","CVE":"CVE-2026-78437","Year":"2026"},"notes":[{"CveYear":"2026","CveId":"78437","Ordinal":"1","NoteData":"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.","Type":"Description","Title":"Apache Tomcat: HTTP/2 DoS via malformed request"}]}}}