CVE-2026-34827

{"id": "CVE-2026-34827", "cveTags": [], "metrics": {"cvssMetricV31": [{"type": "Secondary", "source": "security-advisories@github.com", "cvssData": {"scope": "UNCHANGED", "version": "3.1", "baseScore": 7.5, "attackVector": "NETWORK", "baseSeverity": "HIGH", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H", "integrityImpact": "NONE", "userInteraction": "NONE", "attackComplexity": "LOW", "availabilityImpact": "HIGH", "privilegesRequired": "NONE", "confidentialityImpact": "NONE"}, "impactScore": 3.6, "exploitabilityScore": 3.9}]}, "published": "2026-04-02T18:16:33.490", "references": [{"url": "https://github.com/rack/rack/security/advisories/GHSA-v6x5-cg8r-vv6x", "tags": ["Vendor Advisory", "Mitigation"], "source": "security-advisories@github.com"}], "vulnStatus": "Analyzed", "weaknesses": [{"type": "Primary", "source": "security-advisories@github.com", "description": [{"lang": "en", "value": "CWE-400"}, {"lang": "en", "value": "CWE-407"}, {"lang": "en", "value": "CWE-770"}]}], "descriptions": [{"lang": "en", "value": "Rack is a modular Ruby web server interface. From versions 3.0.0.beta1 to before 3.1.21, and 3.2.0 to before 3.2.6, Rack::Multipart::Parser#handle_mime_head parses quoted multipart parameters such as Content-Disposition: form-data; name=\"...\" using repeated String#index searches combined with String#slice! prefix deletion. For escape-heavy quoted values, this causes super-linear processing. An unauthenticated attacker can send a crafted multipart/form-data request containing many parts with long backslash-escaped parameter values to trigger excessive CPU usage during multipart parsing. This results in a denial of service condition in Rack applications that accept multipart form data. This issue has been patched in versions 3.1.21 and 3.2.6."}], "lastModified": "2026-04-24T12:47:32.790", "configurations": [{"nodes": [{"negate": false, "cpeMatch": [{"criteria": "cpe:2.3:a:rack:rack:*:*:*:*:*:ruby:*:*", "vulnerable": true, "matchCriteriaId": "6948AAA6-873D-46BA-AA22-4C81138128E1", "versionEndExcluding": "3.1.21", "versionStartIncluding": "3.0.0"}, {"criteria": "cpe:2.3:a:rack:rack:*:*:*:*:*:ruby:*:*", "vulnerable": true, "matchCriteriaId": "3FB592AD-E826-49BE-AC6D-E5F55FDCC96E", "versionEndExcluding": "3.2.6", "versionStartIncluding": "3.2.0"}], "operator": "OR"}]}], "sourceIdentifier": "security-advisories@github.com"}