{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-125109","assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","state":"PUBLISHED","assignerShortName":"GitHub_M","dateReserved":"2026-11-09T17:45:35.935Z","datePublished":"2026-11-09T21:57:46.924Z","dateUpdated":"2026-11-10T16:18:06.940Z"},"containers":{"cna":{"title":"Rack: Rack::Request#host_with_port (and #base_url / #url) return the raw invalid Host header — incomplete fix of CVE-2026-34835","problemTypes":[{"descriptions":[{"cweId":"CWE-1286","lang":"en","description":"CWE-1286: Improper Validation of Syntactic Correctness of Input","type":"CWE"}]}],"metrics":[{"cvssV3_1":{"attackComplexity":"HIGH","attackVector":"NETWORK","availabilityImpact":"NONE","baseScore":4.8,"baseSeverity":"MEDIUM","confidentialityImpact":"LOW","integrityImpact":"LOW","privilegesRequired":"NONE","scope":"UNCHANGED","userInteraction":"NONE","vectorString":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N","version":"3.1"}}],"references":[{"name":"https://github.com/rack/rack/security/advisories/GHSA-2j8w-xcrc-x985","tags":["x_refsource_CONFIRM"],"url":"https://github.com/rack/rack/security/advisories/GHSA-2j8w-xcrc-x985"},{"name":"https://github.com/rack/rack/commit/4380381a56dc52556a436d6d794c8e18dc8b0565","tags":["x_refsource_MISC"],"url":"https://github.com/rack/rack/commit/4380381a56dc52556a436d6d794c8e18dc8b0565"},{"name":"https://github.com/rack/rack/commit/49386f460286b7346c7003b69a839de782cc8a39","tags":["x_refsource_MISC"],"url":"https://github.com/rack/rack/commit/49386f460286b7346c7003b69a839de782cc8a39"},{"name":"https://github.com/rack/rack/releases/tag/v3.1.23","tags":["x_refsource_MISC"],"url":"https://github.com/rack/rack/releases/tag/v3.1.23"},{"name":"https://github.com/rack/rack/releases/tag/v3.2.8","tags":["x_refsource_MISC"],"url":"https://github.com/rack/rack/releases/tag/v3.2.8"}],"affected":[{"vendor":"rack","product":"rack","versions":[{"version":">= 3.0, < 3.1.23","status":"affected"},{"version":">= 3.2, < 3.2.8","status":"affected"}]}],"providerMetadata":{"orgId":"a0819718-46f1-4df5-94e2-005712e83aaa","shortName":"GitHub_M","dateUpdated":"2026-11-09T21:57:46.924Z"},"descriptions":[{"lang":"en","value":"Rack is a modular Ruby web server interface. From 3.0 until 3.1.23 and 3.2.8, Rack::Request#host_with_port, #base_url, and #url can return an attacker-controlled invalid authority from Host, X-Forwarded-Host, or Forwarded: host= verbatim. Applications without an independent host allowlist that use these methods for absolute URLs, redirects, or origin-dependent checks can emit attacker-chosen delimiters, enabling redirect manipulation, string-based allowlist bypass, or unescaped markup reflection. Rails overrides these methods and is not expected to be affected. This issue is fixed in versions 3.1.23 and 3.2.8."}],"source":{"advisory":"GHSA-2j8w-xcrc-x985","discovery":"UNKNOWN"}},"adp":[{"metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-11-10T16:17:53.102307Z","id":"CVE-2026-125109","options":[{"Exploitation":"none"},{"Automatable":"no"},{"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":"2026-11-10T16:18:06.940Z"}}]}}