{"id":"CVE-2026-77762","title":"Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition') vulnerability in Apache Tomcat allows an attacker to inject trailer fields into another HTTP/2 request.\n\n\n\nThis issue affects Apache Tomcat: from…","summary":"Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition') vulnerability in Apache Tomcat allows an attacker to inject trailer fields into another HTTP/2 request.\n\n\n\nThis issue affects Apache Tomcat: from…","severity":"high","cvss":8.1,"cvssVector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H","cwe":["CWE-362"],"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 >= 9.0.39 <= 9.0.121","apache_tomcat >= 8.56.59 <= 8.5.100"],"published":"2026-09-23","updated":"2026-09-23","sourceUpdated":"2026-09-23T19:19:18.870","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-77762","references":[{"url":"https://lists.apache.org/thread/y5r9fvjo7ol24mkoyoc0st8bqrfyqcyn","label":"security@apache.org"},{"url":"http://www.openwall.com/lists/oss-security/2026/09/23/23","label":"af854a3a-2127-422b-91ae-364da2661108"}],"tags":["nvd","cve.org"],"ssvc":{"exploitation":"none","automatable":"no","technicalImpact":"total","timestamp":"2026-09-23T15:40:01.556894Z"},"ingestedAt":"2026-09-23T11:22:32.915Z","slug":"CVE-2026-77762","body":"## Overview\n\nConcurrent Execution using Shared Resource with Improper Synchronization ('Race Condition') vulnerability in Apache Tomcat allows an attacker to inject trailer fields into another HTTP/2 request.\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 9.0.39 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 8.5.59 through 8.5.100. Other unsupported versions may also be affected.\n\n\n\n\nUsers are recommended to upgrade to version 11.0.26, 10.1.60, 9.0.122, which fix the issue.\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"twilight","depthScore":45,"depthScoreParts":{"impact":44.6,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[{"seq":209767,"id":"CVE-2026-77762","ts":1790180880043,"field":"cvss","old":null,"new":"8.1"},{"seq":209766,"id":"CVE-2026-77762","ts":1790180880043,"field":"severity","old":"none","new":"high"}]}