{"id":"CVE-2021-42340","aliases":["BIT-tomcat-2021-42340","GHSA-wph7-x527-w3h5"],"url":"https://o3.security/vulnerability/CVE-2021-42340","summary":"Missing Release of Resource after Effective Lifetime in Apache Tomcat","details":"The fix for bug 63362 present in Apache Tomcat 10.1.0-M1 to 10.1.0-M5, 10.0.0-M1 to 10.0.11, 9.0.40 to 9.0.53 and 8.5.60 to 8.5.71 introduced a memory leak. The object introduced to collect metrics for HTTP upgrade connections was not released for WebSocket connections once the connection was closed. This created a memory leak that, over time, could lead to a denial of service via an OutOfMemoryError.","published":"2021-10-14T20:15:09.060Z","modified":"2026-07-08T05:59:58.392031189Z","cvss":{"score":7.5,"severity":"HIGH","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"},"epss":{"score":0.11796,"percentile":0.9587,"asOf":"2026-09-17"},"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"Maven","name":"org.apache.tomcat:tomcat","fixedVersion":"10.1.0-M6"},{"ecosystem":"Maven","name":"org.apache.tomcat:tomcat","fixedVersion":"10.0.12"},{"ecosystem":"Maven","name":"org.apache.tomcat:tomcat","fixedVersion":"9.0.54"},{"ecosystem":"Maven","name":"org.apache.tomcat:tomcat","fixedVersion":"8.5.72"}],"fix":{"url":"https://github.com/apache/tomcat/commit/31d62426645824bdfe076a0c0eafa904d90b4fb9","label":"apache/tomcat@31d6242"},"references":[{"type":"WEB","url":"https://lists.apache.org/thread.html/r8097a2d1550aa78e585fc77e602b9046e6d4099d8d132497c5387784%40%3Ccommits.myfaces.apache.org%3E"},{"type":"ADVISORY","url":"https://kc.mcafee.com/corporate/index?page=content&id=SB10379"},{"type":"ADVISORY","url":"https://lists.apache.org/thread.html/r83a35be60f06aca2065f188ee542b9099695d57ced2e70e0885f905c%40%3Cannounce.tomcat.apache.org%3E"},{"type":"ADVISORY","url":"https://security.gentoo.org/glsa/202208-34"},{"type":"ADVISORY","url":"https://security.netapp.com/advisory/ntap-20211104-0001/"},{"type":"ADVISORY","url":"https://www.debian.org/security/2021/dsa-5009"},{"type":"FIX","url":"https://www.oracle.com/security-alerts/cpuapr2022.html"},{"type":"FIX","url":"https://www.oracle.com/security-alerts/cpujan2022.html"},{"type":"FIX","url":"https://www.oracle.com/security-alerts/cpujul2022.html"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2021-42340"},{"type":"WEB","url":"https://github.com/apache/tomcat/commit/31d62426645824bdfe076a0c0eafa904d90b4fb9"},{"type":"WEB","url":"https://github.com/apache/tomcat/commit/80f1438ec45e77a07b96419808971838d259eb47"},{"type":"WEB","url":"https://github.com/apache/tomcat/commit/d27535bdee95d252418201eb21e9d29476aa6b6a"},{"type":"WEB","url":"https://github.com/apache/tomcat/commit/d5a6660cba7f51589468937bf3bbad4db7810371"},{"type":"WEB","url":"https://tomcat.apache.org/security-9.html"},{"type":"WEB","url":"https://tomcat.apache.org/security-8.html"},{"type":"WEB","url":"https://tomcat.apache.org/security-10.html"},{"type":"WEB","url":"https://security.netapp.com/advisory/ntap-20211104-0001"},{"type":"WEB","url":"https://lists.apache.org/thread.html/r8097a2d1550aa78e585fc77e602b9046e6d4099d8d132497c5387784@%3Ccommits.myfaces.apache.org%3E"},{"type":"PACKAGE","url":"https://github.com/apache/tomcat"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-07-08T05:59:58.392031189Z"}}