{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-126083","assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","state":"PUBLISHED","assignerShortName":"GitHub_M","dateReserved":"2026-11-10T17:07:43.285Z","datePublished":"2026-11-10T21:09:33.682Z","dateUpdated":"2026-11-13T16:22:49.039Z"},"containers":{"cna":{"title":"Action Pack: Possible IP spoofing in Action Dispatch RemoteIp","problemTypes":[{"descriptions":[{"cweId":"CWE-348","lang":"en","description":"CWE-348: Use of Less Trusted Source","type":"CWE"}]}],"metrics":[{"cvssV3_0":{"attackComplexity":"HIGH","attackVector":"NETWORK","availabilityImpact":"NONE","baseScore":7.4,"baseSeverity":"HIGH","confidentialityImpact":"HIGH","integrityImpact":"HIGH","privilegesRequired":"NONE","scope":"UNCHANGED","userInteraction":"NONE","vectorString":"CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N","version":"3.0"}}],"references":[{"name":"https://github.com/rails/rails/security/advisories/GHSA-2gff-2mmg-m73p","tags":["x_refsource_CONFIRM"],"url":"https://github.com/rails/rails/security/advisories/GHSA-2gff-2mmg-m73p"},{"name":"https://github.com/rails/rails/commit/2a01a5ac521184419d9a92fa2c25e102e68cd227","tags":["x_refsource_MISC"],"url":"https://github.com/rails/rails/commit/2a01a5ac521184419d9a92fa2c25e102e68cd227"},{"name":"https://github.com/rails/rails/releases/tag/v8.1.4.1","tags":["x_refsource_MISC"],"url":"https://github.com/rails/rails/releases/tag/v8.1.4.1"}],"affected":[{"vendor":"rails","product":"rails","versions":[{"version":">= 8.1, < 8.1.4.1","status":"affected"}]}],"providerMetadata":{"orgId":"a0819718-46f1-4df5-94e2-005712e83aaa","shortName":"GitHub_M","dateUpdated":"2026-11-10T21:09:33.682Z"},"descriptions":[{"lang":"en","value":"Action Pack is a framework for handling and responding to web requests. From 8.1 until 8.1.4.1, Since Rails 8.1.0, ActionDispatch::RemoteIp derives request.remote_ip from Rack::Request#forwarded_for, which under Rack 3 reads the RFC 7239 Forwarded header in preference to X-Forwarded-For. When a reverse proxy appends the client address to X-Forwarded-For but passes a client-supplied Forwarded header through unchanged, request.remote_ip returns an address chosen by the client, and the IP spoofing check does not raise, because it compares only Client-Ip with the forwarded addresses. An unauthenticated attacker could therefore spoof request.remote_ip, possibly bypassing IP-based access controls and rate limits keyed on the client address (including the default by: of rate_limit), and falsifying the client address in logs. An application is affected if it meets all of these requirements: Runs Rails 8.1.0 through 8.1.4 with Rack 3. Under Rack 2.2, forwarded_for reads only X-Forwarded-For. Is served behind a proxy that does not remove or overwrite a client-supplied Forwarded header. Relies on request.remote_ip for access control, rate limiting, or auditing. The fix detects a spoofed Forwarded header only when the proxy also sets X-Forwarded-For. An application whose proxy passes a client-supplied Forwarded header through and sets no X-Forwarded-For remains exposed after upgrading, and should configure the proxy to remove or overwrite Forwarded, or apply the workaround below. This issue is fixed in version 8.1.4.1."}],"source":{"advisory":"GHSA-2gff-2mmg-m73p","discovery":"UNKNOWN"}},"adp":[{"metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-11-13T16:22:35.722742Z","id":"CVE-2026-126083","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"total"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"title":"CISA ADP Vulnrichment","providerMetadata":{"orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","shortName":"CISA-ADP","dateUpdated":"2026-11-13T16:22:49.039Z"}}]}}