CVE-2026-126083

{"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": "2026-11-10T21:09:33.682Z"}, "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"}}}}

{}

{"affected": [{"affectedData": [{"product": "rails", "vendor": "rails", "versions": [{"status": "affected", "version": ">= 8.1, < 8.1.4.1"}]}], "source": "security-advisories@github.com"}], "cveTags": [], "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."}], "id": "CVE-2026-126083", "lastModified": "2026-11-12T22:18:35.610", "metrics": {"cvssMetricV30": [{"cvssData": {"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"}, "exploitabilityScore": 2.2, "impactScore": 5.2, "source": "security-advisories@github.com", "type": "Secondary"}]}, "published": "2026-11-10T21:19:27.133", "references": [{"source": "security-advisories@github.com", "url": "https://github.com/rails/rails/commit/2a01a5ac521184419d9a92fa2c25e102e68cd227"}, {"source": "security-advisories@github.com", "url": "https://github.com/rails/rails/releases/tag/v8.1.4.1"}, {"source": "security-advisories@github.com", "url": "https://github.com/rails/rails/security/advisories/GHSA-2gff-2mmg-m73p"}], "sourceIdentifier": "security-advisories@github.com", "vulnStatus": "Awaiting Analysis", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-348"}], "source": "security-advisories@github.com", "type": "Primary"}]}

{"bugzilla": {"description": "actionpack: actionpack: IP address spoofing via crafted Forwarded header", "id": "2571280", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2571280"}, "csaw": false, "cvss3": {"cvss3_base_score": "7.4", "cvss3_scoring_vector": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N", "status": "draft"}, "cwe": "CWE-348", "details": ["A flaw was found in Action Pack. When deployed behind a reverse proxy that passes client-supplied headers through unchanged, the remote Internet Protocol (IP) address resolution mechanism prioritizes the Forwarded header over the X-Forwarded-For header without verifying consistency between them. An unauthenticated remote attacker can exploit this vulnerability by submitting a request with a crafted Forwarded header containing an arbitrary address. Successful exploitation allows the attacker to spoof their client IP address, potentially bypassing IP-based access controls and rate limits, as well as falsifying audit logs."], "mitigation": {"lang": "en:us", "value": "Strip or overwrite the RFC 7239 `Forwarded` header at intermediate reverse proxies or ingress controllers before passing requests to the backend application.\nIn Nginx:\n```nginx\nproxy_set_header Forwarded \"\";\n```\nIn Apache HTTP Server:\n```apache\nRequestHeader unset Forwarded\n```\nAlternatively, configure Rack to prioritize `X-Forwarded-For` by setting the following in a Rails application initializer (e.g., `config/initializers/rack.rb`):\n```ruby\nRack::Request.forwarded_priority = [:x_forwarded]\n```\nWarning: Modifying reverse proxy configurations requires reloading or restarting the proxy service (e.g., `systemctl reload httpd` or `systemctl reload nginx`), which may cause brief network interruptions. Disabling the `Forwarded` header causes Rack to ignore RFC 7239 headers when evaluating request scheme, host, and port information."}, "name": "CVE-2026-126083", "package_state": [{"cpe": "cpe:/a:redhat:3scale:2.13", "fix_state": "Not affected", "package_name": "3scale-amp2/system-rhel8", "product_name": "Red Hat 3scale API Management Platform 2"}, {"cpe": "cpe:/a:redhat:3scale:2.13", "fix_state": "Not affected", "package_name": "3scale-amp2/system-rhel9", "product_name": "Red Hat 3scale API Management Platform 2"}, {"cpe": "cpe:/a:redhat:3scale:2.13", "fix_state": "Not affected", "package_name": "3scale-amp2/zync-rhel9", "product_name": "Red Hat 3scale API Management Platform 2"}, {"cpe": "cpe:/a:redhat:satellite:6", "fix_state": "Not affected", "package_name": "rubygem-actionpack", "product_name": "Red Hat Satellite 6"}], "public_date": "2026-11-10T21:09:33Z", "references": ["https://www.cve.org/CVERecord?id=CVE-2026-126083\nhttps://nvd.nist.gov/vuln/detail/CVE-2026-126083\nhttps://github.com/rails/rails/commit/2a01a5ac521184419d9a92fa2c25e102e68cd227\nhttps://github.com/rails/rails/releases/tag/v8.1.4.1\nhttps://github.com/rails/rails/security/advisories/GHSA-2gff-2mmg-m73p"], "statement": "This vulnerability is rated as Important because remote, unauthenticated attackers can spoof their apparent IP address to circumvent IP-based authentication controls and request rate limits. In deployments where reverse proxies do not strip client-injected RFC 7239 headers while appending client addresses to traditional forwarding headers, the application prioritizes the untrusted header without triggering spoof detection checks. Exploitation requires specific proxy architecture preconditions, but a successful attack permits access restriction bypasses and compromises audit trail integrity.", "threat_severity": "Important"}

{"affected": [{"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "generic", "value": "[8.1,8.1.4.1)"}}], "enrichment": {"confidence": 100.0, "confidence_source": "matching", "scores": [{"score": 100.0, "source": "matching"}]}, "original": {"product": "rails", "source": "cna", "vendor": "rails"}, "product": "rails", "vendor": "rails"}], "created": "2026-11-12T01:00:09.863379+00:00", "updated": "2026-11-13T11:30:07.803867+00:00", "vendors": ["rails", "rails$PRODUCT$rails"]}