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{"bugzilla": {"description": "rack: Rack: Denial of Service via crafted Accept-Encoding header", "id": "2454493", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2454493"}, "csaw": false, "cvss3": {"cvss3_base_score": "5.3", "cvss3_scoring_vector": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L", "status": "draft"}, "cwe": "CWE-1050", "details": ["Rack is a modular Ruby web server interface. Prior to versions 2.2.23, 3.1.21, and 3.2.6, Rack::Utils.select_best_encoding processes Accept-Encoding values with quadratic time complexity when the header contains many wildcard (*) entries. Because this method is used by Rack::Deflater to choose a response encoding, an unauthenticated attacker can send a single request with a crafted Accept-Encoding header and cause disproportionate CPU consumption on the compression middleware path. This results in a denial of service condition for applications using Rack::Deflater. This issue has been patched in versions 2.2.23, 3.1.21, and 3.2.6.", "A flaw was found in Rack. An unauthenticated attacker can exploit a vulnerability in the `Rack::Utils.select_best_encoding` method by sending a specially crafted `Accept-Encoding` header with numerous wildcard entries. This leads to quadratic time complexity during processing, causing disproportionate CPU consumption. Consequently, this can result in a Denial of Service (DoS) condition for applications utilizing Rack::Deflater."], "mitigation": {"lang": "en:us", "value": "Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability."}, "name": "CVE-2026-34230", "package_state": [{"cpe": "cpe:/a:redhat:logging:5", "fix_state": "Fix deferred", "package_name": "openshift-logging/cluster-logging-operator-bundle", "product_name": "Logging Subsystem for Red Hat OpenShift"}, {"cpe": "cpe:/a:redhat:logging:5", "fix_state": "Fix deferred", "package_name": "openshift-logging/cluster-logging-rhel9-operator", "product_name": "Logging Subsystem for Red Hat OpenShift"}, {"cpe": "cpe:/a:redhat:logging:5", "fix_state": "Fix deferred", "package_name": "openshift-logging/eventrouter-rhel9", "product_name": "Logging Subsystem for Red Hat 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"rhel9/ruby-33", "product_name": "Red Hat Enterprise Linux 9"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Fix deferred", "package_name": "ubi9/ruby-30", "product_name": "Red Hat Enterprise Linux 9"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Fix deferred", "package_name": "ubi9/ruby-33", "product_name": "Red Hat Enterprise Linux 9"}], "public_date": "2026-04-02T16:41:21Z", "references": ["https://www.cve.org/CVERecord?id=CVE-2026-34230\nhttps://nvd.nist.gov/vuln/detail/CVE-2026-34230\nhttps://github.com/rack/rack/security/advisories/GHSA-v569-hp3g-36wr"], "threat_severity": "Moderate"}

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