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.
Project Subscriptions
No data.
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
Wed, 11 Nov 2026 12:15:00 +0000
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| References |
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| Metrics |
threat_severity
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cvssV3_1
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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 |
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| Metrics |
cvssV3_0
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Projects
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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
OpenCVE Enrichment
No data.
Weaknesses
Github GHSA