{"id":"CVE-2026-42498","aliases":["BIT-tomcat-2026-42498","GHSA-fv25-8xcx-gqjc"],"url":"https://o3.security/vulnerability/CVE-2026-42498","summary":"Apache Tomcat: WebSocket authentication header exposure","details":"Versions Affected:\nApache Tomcat 11.0.0-M1 to 11.0.21\nApache Tomcat 10.1.0-M1 to 10.1.54\nApache Tomcat 9.0.2 to 9.0.117\nOlder, unsupported versions may also be affected\n\nDescription:\nIf a WebSocket request was redirected after authentication, Tomcat's\nWebSocket client would present the most recent authentication header to\nthe redirect target host.\n\nMitigation:\nUsers of the affected versions should apply one of the following\nmitigations:\n- Upgrade to Apache Tomcat 11.0.22 or later\n- Upgrade to Apache Tomcat 10.1.55 or later\n- Upgrade to Apache Tomcat 9.0.118 or later\n\nCredit:\nThis issue was identified by lokerxx","published":"2026-05-12T15:17:56.531Z","modified":"2026-09-22T12:41:42.327849999Z","cvss":{"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"},"epss":{"score":0.00646,"percentile":0.49257,"asOf":"2026-09-16"},"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"Maven","name":"org.apache.tomcat.embed:tomcat-embed-core","fixedVersion":"9.0.118"},{"ecosystem":"Maven","name":"org.apache.tomcat.embed:tomcat-embed-core","fixedVersion":"10.1.55"},{"ecosystem":"Maven","name":"org.apache.tomcat.embed:tomcat-embed-core","fixedVersion":"11.0.22"},{"ecosystem":"Maven","name":"org.apache.tomcat:tomcat","fixedVersion":"9.0.118"},{"ecosystem":"Maven","name":"org.apache.tomcat:tomcat","fixedVersion":"10.1.55"},{"ecosystem":"Maven","name":"org.apache.tomcat:tomcat","fixedVersion":"11.0.22"},{"ecosystem":"Maven","name":"org.apache.tomcat:tomcat-catalina","fixedVersion":"9.0.118"},{"ecosystem":"Maven","name":"org.apache.tomcat:tomcat-catalina","fixedVersion":"10.1.55"},{"ecosystem":"Maven","name":"org.apache.tomcat:tomcat-catalina","fixedVersion":"11.0.22"}],"fix":{"url":"https://github.com/apache/tomcat/commit/169d725788ea6aec217ecac70fe4161c837ba423","label":"apache/tomcat@169d725"},"references":[{"type":"WEB","url":"http://www.openwall.com/lists/oss-security/2026/05/12/14"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/42xxx/CVE-2026-42498.json"},{"type":"ADVISORY","url":"https://lists.apache.org/thread/n61zwf75jrv09rz90j4jssncm244bwdb"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-42498"},{"type":"WEB","url":"https://github.com/apache/tomcat/commit/169d725788ea6aec217ecac70fe4161c837ba423"},{"type":"WEB","url":"https://github.com/apache/tomcat/commit/6cbe274592ef2d11607b5b188e1df649de52f8d5"},{"type":"WEB","url":"https://github.com/apache/tomcat/commit/b7b173694d588ddcfa432f079baf763cbbbaa5c4"},{"type":"PACKAGE","url":"https://github.com/apache/tomcat"},{"type":"WEB","url":"https://tomcat.apache.org/security-10.html"},{"type":"WEB","url":"https://tomcat.apache.org/security-11.html"},{"type":"WEB","url":"https://tomcat.apache.org/security-9.html"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-09-22T12:41:42.327849999Z"}}