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.
Metrics
Affected Vendors & Products
Advisories
| Source | ID | Title |
|---|---|---|
Github GHSA |
GHSA-2gff-2mmg-m73p | Action Pack: Possible IP spoofing in Action Dispatch RemoteIp |
Fixes
Solution
No solution given by the vendor.
Workaround
No workaround given by the vendor.
References
History
Tue, 10 Nov 2026 21:15:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Description | 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. | |
| Title | Action Pack: Possible IP spoofing in Action Dispatch RemoteIp | |
| Weaknesses | CWE-348 | |
| References |
| |
| Metrics |
cvssV3_0
|
Projects
Sign in to view the affected projects.
Status: PUBLISHED
Assigner: GitHub_M
Published:
Updated: 2026-11-10T21:09:33.682Z
Reserved: 2026-11-10T17:07:43.285Z
Link: CVE-2026-126083
No data.
Status : Received
Published: 2026-11-10T21:19:27.133
Modified: 2026-11-10T21:19:27.133
Link: CVE-2026-126083
No data.
OpenCVE Enrichment
No data.
Weaknesses
Github GHSA