CVE-2026-126083: rails · Use of Less Trusted Source
Affects railsSource CVE Database V5
Not known to be exploited · CVSS 7.4 High : upgrade to 8.1.4.1 soon.
Data as of 10 Nov 2026, 21:20 UTC
Thin evidence
One scorer or none| CNA (GitHub_M) | CVSS 3.0 | 7.4 |
|---|
- Patch
- Available – fixed in 8.1.4.1
CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:NExploitation evidence
Disclosed: evidence found.
CVE published 10 Nov 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 10 Nov 2026.
What to do
Upgrade rails to 8.1.4.1.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| railsrails | Affected
| Fixed in
|
AI-suggested
Upgrade Rails to version 8.1.4.1 or later, where the vulnerability is fixed. If upgrading is not immediately possible, configure the reverse proxy to remove or overwrite any client-supplied Forwarded headers to prevent spoofing. Applications behind proxies that pass client-supplied Forwarded headers without setting X-Forwarded-For remain vulnerable even after upgrading, so proxy configuration is critical. No other mitigation actions are specifically recommended.
Description
A vulnerability in Rails Action Pack versions 8.1.0 through 8.1.4 allows an attacker to spoof the client IP address by exploiting how request.remote_ip is derived from the Forwarded header when used with Rack 3. This can lead to bypassing IP-based access controls, rate limiting, and falsified client IP logging. The issue is fixed in version 8.1.4.1.