CVE-2026-68763

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{"bugzilla": {"description": "org.apache.tomcat/tomcat: Apache Tomcat: Denial of Service via HTTP/2 allocation leak", "id": "2524166", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2524166"}, "csaw": false, "cvss3": {"cvss3_base_score": "7.5", "cvss3_scoring_vector": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H", "status": "draft"}, "cwe": "CWE-770", "details": ["Uncontrolled Resource Consumption vulnerability in Apache Tomcat\u00a0via an allocation leak in the HTTP/2 backlog tracking when a stream is reset\nThis issue affects Apache Tomcat: from 11.0.0-M1 through 11.0.24, from 10.1.0-M1 through 10.1.57, from 9.0.39 through 9.0.120.\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.\u00a0Other unsupported versions may also be affected.\nUsers are recommended to upgrade to version 11.0.25, 10.1.58 or 9.0.121, which fix the issue.", "A flaw was found in Apache Tomcat. This vulnerability, an uncontrolled resource consumption issue, arises from an allocation leak in the HTTP/2 backlog tracking when a stream is reset. A remote attacker could exploit this to cause a Denial of Service (DoS), making the server unresponsive or unavailable to users."], "mitigation": {"lang": "en:us", "value": "To mitigate this vulnerability, disable the HTTP/2 protocol in Apache Tomcat if it is not required for your deployment. This can be achieved by commenting out or removing the <UpgradeProtocol className=\"org.apache.coyote.http2.Http2Protocol\" /> element within the <Connector> configuration in the server.xml file. After modifying server.xml, a restart of the Apache Tomcat service is required for the changes to take effect."}, "name": "CVE-2026-68763", "package_state": [{"cpe": "cpe:/o:redhat:enterprise_linux:10", "fix_state": "Under investigation", "package_name": "tomcat", "product_name": "Red Hat Enterprise Linux 10"}, {"cpe": "cpe:/o:redhat:enterprise_linux:10", "fix_state": "Under investigation", "package_name": "tomcat9", "product_name": "Red Hat Enterprise Linux 10"}, {"cpe": "cpe:/o:redhat:enterprise_linux:6", "fix_state": "Under investigation", "package_name": "tomcat6", "product_name": "Red Hat Enterprise Linux 6"}, {"cpe": "cpe:/o:redhat:enterprise_linux:7", "fix_state": "Under investigation", "package_name": "tomcat", "product_name": "Red Hat Enterprise Linux 7"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Under investigation", "package_name": "pki-deps:10.6/pki-servlet-engine", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Under investigation", "package_name": "tomcat", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Under investigation", "package_name": "tomcat", "product_name": "Red Hat Enterprise Linux 9"}, {"cpe": "cpe:/a:redhat:hummingbird:1", "fix_state": "Under investigation", "package_name": "tomcat10", "product_name": "Red Hat Hardened Images"}, {"cpe": "cpe:/a:redhat:hummingbird:1", "fix_state": "Under investigation", "package_name": "tomcat11", "product_name": "Red Hat Hardened Images"}, {"cpe": "cpe:/a:redhat:jboss_enterprise_web_server:5", "fix_state": "Out of support scope", "package_name": "tomcat", "product_name": "Red Hat JBoss Web Server 5"}, {"cpe": "cpe:/a:redhat:jboss_enterprise_web_server:6", "fix_state": "Affected", "package_name": "tomcat", "product_name": "Red Hat JBoss Web Server 6"}, {"cpe": "cpe:/a:redhat:jboss_enterprise_web_server:7", "fix_state": "Affected", "package_name": "tomcat", "product_name": "Red Hat JBoss Web Server 7"}], "public_date": "2026-08-25T22:00:37Z", "references": ["https://www.cve.org/CVERecord?id=CVE-2026-68763\nhttps://nvd.nist.gov/vuln/detail/CVE-2026-68763\nhttps://lists.apache.org/thread/tv51ty39ppv41v04hdtkp9dp7tg02nzl"], "statement": "This Important flaw in Apache Tomcat, as shipped with Red Hat JBoss Web Server, allows a remote, unauthenticated attacker to cause a denial of service. The vulnerability stems from an allocation leak in the HTTP/2 backlog tracking, which can be triggered by resetting an HTTP/2 stream, leading to resource exhaustion and service unavailability.", "threat_severity": "Important"}

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