{"id":"CVE-2026-77756","title":"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 ano…","summary":"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 ano…","severity":"low","cvss":3.7,"cvssVector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L","cwe":["CWE-444"],"vendor":"Apache Software Foundation","product":"Apache Tomcat","affected":["apache_tomcat >= 11.0.0-M1 <= 11.0.25","apache_tomcat >= 10.1.0-M1 <= 10.1.59","apache_tomcat >= 9.0.47 <= 9.0.121","apache_tomcat >= 8.5.67 <= 8.5.100"],"published":"2026-09-23","updated":"2026-09-23","sourceUpdated":"2026-09-23T19:19:18.720","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-77756","references":[{"url":"https://lists.apache.org/thread/bl5b6rxqh3vb2k9bj2794vhor7o6xl3z","label":"security@apache.org"},{"url":"http://www.openwall.com/lists/oss-security/2026/09/23/22","label":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-77756.json"},{"url":"https://access.redhat.com/security/cve/CVE-2026-77756"},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2539351"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-77756"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-77756"},{"url":"https://access.redhat.com/errata/RHSA-2026:68257"},{"url":"https://access.redhat.com/errata/RHSA-2026:68258"}],"tags":["nvd","cve.org","csaf","vex","red-hat"],"ssvc":{"exploitation":"none","automatable":"no","technicalImpact":"partial","timestamp":"2026-09-23T13:18:16.430403Z"},"ingestedAt":"2026-09-23T11:22:32.915Z","epss":0.00526,"epssPercentile":0.44377,"patched":["hardened_images"],"scores":{"nvd":3.7,"vendor":5.3},"slug":"CVE-2026-77756","body":"## Overview\n\nInconsistent 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.\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.\n\n## Vendor advisories\n\n- **RHSA-2026:68257** · Red Hat · fixed in: Red Hat Hardened Images · released 2026-09-16 · [advisory](https://access.redhat.com/errata/RHSA-2026:68257)\n- **RHSA-2026:68258** · Red Hat · fixed in: Red Hat Hardened Images · released 2026-09-16 · [advisory](https://access.redhat.com/errata/RHSA-2026:68258)\n- **Red Hat VEX** · Moderate · affected: Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 6, Red Hat Enterprise Linux 7, Red Hat Enterprise Linux 8, Red Hat Enterprise Linux 9, Red Hat JBoss Web Server 5, … · updated 2026-09-29 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-77756.json)","depth":"sunlit","depthScore":20,"depthScoreParts":{"impact":20.4,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[{"seq":209687,"id":"CVE-2026-77756","ts":1790173570470,"field":"cvss","old":null,"new":"3.7"},{"seq":209686,"id":"CVE-2026-77756","ts":1790173570470,"field":"severity","old":"none","new":"low"}]}