{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-34230","assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","state":"PUBLISHED","assignerShortName":"GitHub_M","dateReserved":"2026-03-26T16:22:29.034Z","datePublished":"2026-04-02T16:41:21.095Z","dateUpdated":"2026-04-03T18:19:00.388Z"},"containers":{"cna":{"title":"Rack: Quadratic complexity in Rack::Utils.select_best_encoding via wildcard Accept-Encoding header","problemTypes":[{"descriptions":[{"cweId":"CWE-400","lang":"en","description":"CWE-400: Uncontrolled Resource Consumption","type":"CWE"}]},{"descriptions":[{"cweId":"CWE-407","lang":"en","description":"CWE-407: Inefficient Algorithmic Complexity","type":"CWE"}]}],"metrics":[{"cvssV3_1":{"attackComplexity":"LOW","attackVector":"NETWORK","availabilityImpact":"LOW","baseScore":5.3,"baseSeverity":"MEDIUM","confidentialityImpact":"NONE","integrityImpact":"NONE","privilegesRequired":"NONE","scope":"UNCHANGED","userInteraction":"NONE","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L","version":"3.1"}}],"references":[{"name":"https://github.com/rack/rack/security/advisories/GHSA-v569-hp3g-36wr","tags":["x_refsource_CONFIRM"],"url":"https://github.com/rack/rack/security/advisories/GHSA-v569-hp3g-36wr"}],"affected":[{"vendor":"rack","product":"rack","versions":[{"version":"< 2.2.23","status":"affected"},{"version":">= 3.0.0.beta1, < 3.1.21","status":"affected"},{"version":">= 3.2.0, < 3.2.6","status":"affected"}]}],"providerMetadata":{"orgId":"a0819718-46f1-4df5-94e2-005712e83aaa","shortName":"GitHub_M","dateUpdated":"2026-04-02T16:41:21.095Z"},"descriptions":[{"lang":"en","value":"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."}],"source":{"advisory":"GHSA-v569-hp3g-36wr","discovery":"UNKNOWN"}},"adp":[{"metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-04-02T18:56:03.220311Z","id":"CVE-2026-34230","options":[{"Exploitation":"none"},{"Automatable":"yes"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"title":"CISA ADP Vulnrichment","providerMetadata":{"orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","shortName":"CISA-ADP","dateUpdated":"2026-04-03T18:19:00.388Z"}}]}}