{"id":"CVE-2026-77756","state":"PUBLISHED","title":"Apache Tomcat: Transfer-Encoding honored for HTTP/1.0 requests","description":"Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling') vulnerability in Apache Tomcat caused by processing the transfer-encoding header for an HTTP/1.0 request may allow an attacker to cause one request from another user to fail when Tomcat is located behind a reverse proxy.\n\n\n\nThis issue affects Apache Tomcat: from 11.0.0-M1 through 11.0.25, from 10.1.0-M1 through 10.1.59, from 9.0.47 through 9.0.121.\n\n\n\nThe following versions were EOL at the time the CVE was created but are \nknown to be affected: from 8.5.67 through 8.5.100. Other unsupported versions may also be affected.\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":"2026-09-23T11:18:02.672Z","updatedAt":"2026-09-23T18:10:42.842Z","severity":{"score":3.7,"label":"Low","version":"3.1","vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/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":"11.0.0-M1","status":"affected","lessThanOrEqual":"11.0.25","versionType":"semver"},{"version":"10.1.0-M1","status":"affected","lessThanOrEqual":"10.1.59","versionType":"semver"},{"version":"9.0.47","status":"affected","lessThanOrEqual":"9.0.121","versionType":"semver"},{"version":"8.5.67","status":"affected","lessThanOrEqual":"8.5.100","versionType":"semver"},{"version":"0","status":"unaffected","lessThanOrEqual":"7.0.109","versionType":"semver"}]}],"references":["https://lists.apache.org/thread/bl5b6rxqh3vb2k9bj2794vhor7o6xl3z","http://www.openwall.com/lists/oss-security/2026/09/23/22"],"weaknesses":["CWE-444"],"ingestedAt":"2026-10-29T20:13:07.220Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/77xxx/CVE-2026-77756.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-77756","state":"PUBLISHED","datePublished":"2026-09-23T11:18:02.672Z","dateUpdated":"2026-09-23T18:10:42.842Z","assignerShortName":"apache","assignerOrgId":"f0158376-9dc2-43b6-827c-5f631a4d8d09","dateReserved":"2026-08-21T09:55:42.227Z"},"containers":{"cna":{"title":"Apache Tomcat: Transfer-Encoding honored for HTTP/1.0 requests","descriptions":[{"lang":"en","value":"Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling') vulnerability in Apache Tomcat caused by processing the transfer-encoding header for an HTTP/1.0 request may allow an attacker to cause one request from another user to fail when Tomcat is located behind a reverse proxy.\n\n\n\nThis issue affects Apache Tomcat: from 11.0.0-M1 through 11.0.25, from 10.1.0-M1 through 10.1.59, from 9.0.47 through 9.0.121.\n\n\n\nThe following versions were EOL at the time the CVE was created but are \nknown to be affected: from 8.5.67 through 8.5.100. Other unsupported versions may also be affected.\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":"11.0.0-M1","status":"affected","lessThanOrEqual":"11.0.25","versionType":"semver"},{"version":"10.1.0-M1","status":"affected","lessThanOrEqual":"10.1.59","versionType":"semver"},{"version":"9.0.47","status":"affected","lessThanOrEqual":"9.0.121","versionType":"semver"},{"version":"8.5.67","status":"affected","lessThanOrEqual":"8.5.100","versionType":"semver"},{"version":"0","status":"unaffected","lessThanOrEqual":"7.0.109","versionType":"semver"}]}],"references":[{"url":"https://lists.apache.org/thread/bl5b6rxqh3vb2k9bj2794vhor7o6xl3z","tags":["vendor-advisory"]}],"metrics":[{"other":{"type":"Textual description of severity","content":{"text":"low"}},"scenarios":[{"lang":"en","value":"GENERAL"}]}],"problemTypes":[{"descriptions":[{"cweId":"CWE-444","description":"CWE-444 Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling')","lang":"en","type":"CWE"}]}],"providerMetadata":{"shortName":"apache","orgId":"f0158376-9dc2-43b6-827c-5f631a4d8d09","dateUpdated":"2026-09-23T11:18:02.672Z"},"source":{"discovery":"INTERNAL"},"x_generator":{"engine":"Vulnogram 0.2.0"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"cvssV3_1":{"scope":"UNCHANGED","version":"3.1","baseScore":3.7,"attackVector":"NETWORK","baseSeverity":"LOW","vectorString":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L","integrityImpact":"NONE","userInteraction":"NONE","attackComplexity":"HIGH","availabilityImpact":"LOW","privilegesRequired":"NONE","confidentialityImpact":"NONE"}},{"other":{"type":"ssvc","content":{"timestamp":"2026-09-23T13:18:16.430403Z","id":"CVE-2026-77756","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-09-23T13:18:19.230Z"}},{"title":"CVE Program Container","references":[{"url":"http://www.openwall.com/lists/oss-security/2026/09/23/22"}],"providerMetadata":{"shortName":"CVE","orgId":"af854a3a-2127-422b-91ae-364da2661108","dateUpdated":"2026-09-23T18:10:42.842Z"}}]}}}